oasis

OData Version 4.01. Part 2: URL Conventions

Committee Specification Draft 03 /
Public Review Draft 03

28 September 2017

Specification URIs

This version:

http://docs.oasis-open.org/odata/odata/v4.01/csprd03/part2-url-conventions/odata-v4.01-csprd03-part2-url-conventions.docx (Authoritative)

http://docs.oasis-open.org/odata/odata/v4.01/csprd03/part2-url-conventions/odata-v4.01-csprd03-part2-url-conventions.html

http://docs.oasis-open.org/odata/odata/v4.01/csprd03/part2-url-conventions/odata-v4.01-csprd03-part2-url-conventions.pdf

Previous version:

http://docs.oasis-open.org/odata/odata/v4.01/csprd02/part2-url-conventions/odata-v4.01-csprd02-part2-url-conventions.docx (Authoritative)

http://docs.oasis-open.org/odata/odata/v4.01/csprd02/part2-url-conventions/odata-v4.01-csprd02-part2-url-conventions.html

http://docs.oasis-open.org/odata/odata/v4.01/csprd02/part2-url-conventions/odata-v4.01-csprd02-part2-url-conventions.pdf

Latest version:

http://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part2-url-conventions.docx (Authoritative)

http://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part2-url-conventions.html

http://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part2-url-conventions.pdf

Technical Committee:

OASIS Open Data Protocol (OData) TC

Chairs:

Ralf Handl (ralf.handl@sap.com), SAP SE

Michael Pizzo (mikep@microsoft.com), Microsoft

Editors:

Michael Pizzo (mikep@microsoft.com), Microsoft

Ralf Handl (ralf.handl@sap.com), SAP SE

Martin Zurmuehl (martin.zurmuehl@sap.com), SAP SE

Additional artifacts:

This prose specification is one component of a Work Product that also includes:

·         OData Version 4.01. Part 1: Protocol. http://docs.oasis-open.org/odata/odata/v4.01/csprd03/part1-protocol/odata-v4.01-csprd03-part1-protocol.html.

·         OData Version 4.01. Part 2: URL Conventions (this document). http://docs.oasis-open.org/odata/odata/v4.01/csprd03/part2-url-conventions/odata-v4.01-csprd03-part2-url-conventions.html.

·         ABNF components: OData ABNF Construction Rules Version 4.01 and OData ABNF Test Cases Version 4.01. http://docs.oasis-open.org/odata/odata/v4.01/csprd03/abnf/.

Related work:

This specification replaces or supersedes:

·         OData Version 4.0 Part 2: URL Conventions. Edited by Michael Pizzo, Ralf Handl, and Martin Zurmuehl. 24 February 2014. OASIS Standard. http://docs.oasis-open.org/odata/odata/v4.0/os/part2-url-conventions/odata-v4.0-os-part2-url-conventions.html. Latest version: http://docs.oasis-open.org/odata/odata/v4.0/odata-v4.0-part2-url-conventions.html.

This specification is related to:

·         OData Vocabularies Version 4.0. Edited by Michael Pizzo, Ralf Handl, and Ram Jeyaraman. Latest version: http://docs.oasis-open.org/odata/odata-vocabularies/v4.0/odata-vocabularies-v4.0.html.

·         OData Common Schema Definition Language (CSDL) JSON Representation Version 4.01. Edited by Michael Pizzo, Ralf Handl, and Martin Zurmuehl. Latest version: http://docs.oasis-open.org/odata/odata-csdl-json/v4.01/odata-csdl-json-v4.01.html.

·         OData Common Schema Definition Language (CSDL) XML Representation Version 4.01. Edited by Michael Pizzo, Ralf Handl, and Martin Zurmuehl. Latest version: http://docs.oasis-open.org/odata/odata-csdl-xml/v4.01/odata-csdl-xml-v4.01.html.

·         OData JSON Format Version 4.01. Edited by Ralf Handl, Michael Pizzo, and Mark Biamonte. Latest version: http://docs.oasis-open.org/odata/odata-json-format/v4.01/odata-json-format-v4.01.html.

·         OData Extension for Data Aggregation Version 4.0. Edited by Ralf Handl, Hubert Heijkers, Gerald Krause, Michael Pizzo, and Martin Zurmuehl. Latest version: http://docs.oasis-open.org/odata/odata-data-aggregation-ext/v4.0/odata-data-aggregation-ext-v4.0.html.

Abstract:

The Open Data Protocol (OData) enables the creation of REST-based data services, which allow resources, identified using Uniform Resource Locators (URLs) and defined in a data model, to be published and edited by Web clients using simple HTTP messages. This specification defines a set of recommended (but not required) rules for constructing URLs to identify the data and metadata exposed by an OData service as well as a set of reserved URL query string operators.

Status:

This document was last revised or approved by the OASIS Open Data Protocol (OData) TC on the above date. The level of approval is also listed above. Check the “Latest version” location noted above for possible later revisions of this document. Any other numbered Versions and other technical work produced by the Technical Committee (TC) are listed at https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=odata#technical.)

TC members should send comments on this specification to the TC’s email list. Others should send comments to the TC’s public comment list, after subscribing to it by following the instructions at the “Send A Comment” button on the TC’s web page at https://www.oasis-open.org/committees/odata/.

This Committee Specification Public Review Draft is provided under the RF on RAND Terms Mode of the OASIS IPR Policy, the mode chosen when the Technical Committee was established. For information on whether any patents have been disclosed that may be essential to implementing this specification, and any offers of patent licensing terms, please refer to the Intellectual Property Rights section of the TC’s web page (https://www.oasis-open.org/committees/odata/ipr.php).

Note that any machine-readable content (Computer Language Definitions) declared Normative for this Work Product is provided in separate plain text files. In the event of a discrepancy between any such plain text file and display content in the Work Product's prose narrative document(s), the content in the separate plain text file prevails.

Citation format:

When referencing this specification the following citation format should be used:

[OData-Part2]

OData Version 4.01. Part 2: URL Conventions. Edited by Michael Pizzo, Ralf Handl, and Martin Zurmuehl. 28 September 2017. OASIS Committee Specification Draft 03 / Public Review Draft 03. http://docs.oasis-open.org/odata/odata/v4.01/csprd03/part2-url-conventions/odata-v4.01-csprd03-part2-url-conventions.html. Latest version: http://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part2-url-conventions.html.

Notices

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Table of Contents

1        Introduction. 8

1.0 IPR Policy. 8

1.1 Terminology. 8

1.2 Normative References. 8

1.3 Typographical Conventions. 9

2        URL Components. 10

3        Service Root URL. 12

4        Resource Path. 13

4.1 Addressing the Model for a Service. 13

4.2 Addressing the Batch Endpoint for a Service. 13

4.3 Addressing Entities. 13

4.3.1 Canonical URL. 15

4.3.2 Canonical URL for Contained Entities. 16

4.3.3 URLs for Related Entities with Referential Constraints. 16

4.3.4 Resolving an Entity-Id. 16

4.3.5 Alternate Keys. 16

4.3.6 Key-as-Segment Convention. 17

4.4 Addressing References between Entities. 18

4.5 Addressing Operations. 18

4.5.1 Addressing Actions. 18

4.5.2 Addressing Functions. 18

4.6 Addressing a Property. 19

4.7 Addressing a Property Value. 19

4.8 Addressing the Count of a Collection. 19

4.9 Addressing a Member within an Entity Collection. 20

4.10 Addressing a Member of an Ordered Collection. 20

4.11 Addressing Derived Types. 20

4.12 Addressing a Subset of a Collection. 21

4.13 Addressing Each Member of a Collection. 21

4.14 Addressing the Media Stream of a Media Entity. 22

4.15 Addressing the Cross Join of Entity Sets. 22

4.16 Addressing All Entities in a Service. 23

5        Query Options. 24

5.1 System Query Options. 24

5.1.1 System Query Option $filter. 24

5.1.1.1 Logical Operators. 24

5.1.1.1.1 Equals. 25

5.1.1.1.2 Not Equals. 25

5.1.1.1.3 Greater Than. 25

5.1.1.1.4 Greater Than or Equal 26

5.1.1.1.5 Less Than. 26

5.1.1.1.6 Less Than or Equal 26

5.1.1.1.7 And. 26

5.1.1.1.8 Or 26

5.1.1.1.9 Not 26

5.1.1.1.10 Has. 26

5.1.1.1.11 In. 26

5.1.1.1.12 Logical Operator Examples. 27

5.1.1.2 Arithmetic Operators. 27

5.1.1.2.1 Addition. 27

5.1.1.2.2 Subtraction. 28

5.1.1.2.3 Negation. 28

5.1.1.2.4 Multiplication. 28

5.1.1.2.5 Division. 28

5.1.1.2.6 Modulo. 29

5.1.1.2.7 Arithmetic Operator Examples. 29

5.1.1.3 Grouping. 29

5.1.1.4 Canonical Functions. 30

5.1.1.5 String and Collection Functions. 30

5.1.1.5.1 concat. 30

5.1.1.5.2 contains. 30

5.1.1.5.3 endswith. 30

5.1.1.5.4 indexof. 31

5.1.1.5.5 length. 31

5.1.1.5.6 startswith. 31

5.1.1.5.7 substring. 32

5.1.1.6 Collection Functions. 32

5.1.1.6.1 hassubset. 32

5.1.1.6.2 hassubsequence. 33

5.1.1.7 String Functions. 33

5.1.1.7.1 tolower. 33

5.1.1.7.2 toupper. 33

5.1.1.7.3 trim. 34

5.1.1.8 Date and Time Functions. 34

5.1.1.8.1 date. 34

5.1.1.8.2 day. 34

5.1.1.8.3 fractionalseconds. 34

5.1.1.8.4 hour. 35

5.1.1.8.5 maxdatetime. 35

5.1.1.8.6 mindatetime. 35

5.1.1.8.7 minute. 35

5.1.1.8.8 month. 35

5.1.1.8.9 now. 36

5.1.1.8.10 second. 36

5.1.1.8.11 time. 36

5.1.1.8.12 totaloffsetminutes. 36

5.1.1.8.13 totalseconds. 36

5.1.1.8.14 year. 37

5.1.1.9 Arithmetic Functions. 37

5.1.1.9.1 ceiling. 37

5.1.1.9.2 floor. 37

5.1.1.9.3 round. 37

5.1.1.10 Type Functions. 38

5.1.1.10.1 cast. 38

5.1.1.10.2 isof. 38

5.1.1.11 Geo Functions. 39

5.1.1.11.1 geo.distance. 39

5.1.1.11.2 geo.intersects. 39

5.1.1.11.3 geo.length. 39

5.1.1.12 Lambda Operators. 39

5.1.1.12.1 any. 39

5.1.1.12.2 all. 40

5.1.1.13 Literals. 40

5.1.1.13.1 Primitive Literals. 40

5.1.1.13.2 Complex and Collection Literals. 40

5.1.1.13.3 null. 41

5.1.1.13.4 $it. 41

5.1.1.13.5 $root. 41

5.1.1.13.6 $this. 42

5.1.1.14 Path Expressions. 42

5.1.1.15 Annotation Values in Expressions. 42

5.1.1.16 Operator Precedence. 43

5.1.1.17 Numeric Promotion. 44

5.1.2 System Query Option $expand. 44

5.1.3 System Query Option $select. 47

5.1.4 System Query Option $orderby. 49

5.1.5 System Query Options $top and $skip. 49

5.1.6 System Query Option $count. 49

5.1.7 System Query Option $search. 49

5.1.7.1 Search Expressions. 49

5.1.8 System Query Option $format. 50

5.1.9 System Query Option $compute. 50

5.1.10 System Query Option $index. 50

5.1.11 System Query Option $schemaversion. 50

5.2 Custom Query Options. 51

5.3 Parameter Aliases. 51

6        Conformance. 52

Appendix A.        Acknowledgments. 53

Appendix B.        Revision History. 54

 


1     Introduction

The Open Data Protocol (OData) enables the creation of REST-based data services, which allow resources, identified using Uniform Resource Locators (URLs) and defined in a data model, to be published and edited by Web clients using simple HTTP messages. This specification defines a set of recommended (but not required) rules for constructing URLs to identify the data and metadata exposed by an OData service as well as a set of reserved URL query string operators, which if accepted by an OData service, MUST be implemented as required by this document.

The [OData-JSON] document specifies the format of the resource representations that are exchanged using OData and the [OData-Protocol] document describes the actions that can be performed on the URLs (optionally constructed following the conventions defined in this document) embedded in those representations.

Services are encouraged to follow the URL construction conventions defined in this specification when possible as consistency promotes an ecosystem of reusable client components and libraries.

1.0 IPR Policy

This Committee Specification Public Review Draft is provided under the RF on RAND Terms Mode of the OASIS IPR Policy, the mode chosen when the Technical Committee was established. For information on whether any patents have been disclosed that may be essential to implementing this specification, and any offers of patent licensing terms, please refer to the Intellectual Property Rights section of the TC’s web page (https://www.oasis-open.org/committees/odata/ipr.php).

1.1 Terminology

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in [RFC2119].

1.2 Normative References

[OData-ABNF]                 OData ABNF Construction Rules Version 4.01.
See the link in "Additional artifacts" section on cover page.

[OData-CSDLJSON]        OData Common Schema Definition Language (CSDL) JSON Representation Version 4.01). See link in "Related work" section on cover page.

[OData-CSDLXML]          OData Common Schema Definition Language (CSDL) XML Representation Version 4.01. See link in "Related work" section on cover page

[OData-JSON]                 OData JSON Format Version 4.01.
See link in "Related work" section on cover page.

[OData-Protocol]            OData Version 4.01 Part 1: Protocol.
See link in "Additional artifacts" section on cover page.

[OData-VocCap]              OData Vocabularies Version 4.0: Capabilities Vocabulary.
See link in "Related work" section on cover page.

[OData-VocCore]            OData Vocabularies Version 4.0: Core Vocabulary.
See link in "Related work" section on cover page.

[RFC2119]                      Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels”, BCP 14, RFC 2119, March 1997. https://tools.ietf.org/html/rfc2119.

[RFC3986]                      Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax”, STD 66, RFC 3986, January 2005. https://tools.ietf.org/html/rfc3986.

[XML-Schema-2]             W3C XML Schema Definition Language (XSD) 1.1 Part 2: DatatypesW3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes, D. Peterson, S. Gao, C. M. Sperberg-McQueen, H. S. Thompson, P. V. Biron, A. Malhotra, Editors, W3C Recommendation, 5 April 2012, http://www.w3.org/TR/2012/REC-xmlschema11-2-20120405/.
Latest version available at http://www.w3.org/TR/xmlschema11-2/.

1.3 Typographical Conventions

Keywords defined by this specification use this monospaced font.

Normative source code uses this paragraph style.

Some sections of this specification are illustrated with non-normative examples.

Example 1: text describing an example uses this paragraph style

Non-normative examples use this paragraph style.

All examples in this document are non-normative and informative only.

All other text is normative unless otherwise labeled.

2     URL Components

A URL used by an OData service has at most three significant parts: the service root URL, resource path and query options. Additional URL constructs (such as a fragment) can be present in a URL used by an OData service; however, this specification applies no further meaning to such additional constructs.

Example 2: OData URL broken down into its component parts:

http://host:port/path/SampleService.svc/Categories(1)/Products?$top=2&$orderby=Name
\______________________________________/\____________________/ \__________________/
                  |                               |                       |
          service root URL                  resource path           query options

Mandated and suggested content of these three significant URL components used by an OData service are covered in sequence in the three following chapters.

OData follows the URI syntax rules defined in [RFC3986] and in addition assigns special meaning to several of the sub-delimiters defined by [RFC3986], so special care has to be taken regarding parsing and percent-decoding.

[RFC3986] defines three steps for URL processing that MUST be performed before percent-decoding:

·       Split undecoded URL into components scheme, hier-part, query, and fragment at first ":", then first "?", and then first "#"

·       Split undecoded hier-part into authority and path

·       Split undecoded path into path segments at "/"

After applying these steps defined by RFC3986 the following steps MUST be performed:

·       Split undecoded query at "&" into query options, and each query option at the first "=" into query option name and query option value

·       Percent-decode path segments, query option names, and query option values exactly once

·       Interpret path segments, query option names, and query option values according to OData rules

The OData rules are defined in this document and the [OData-ABNF]. Note that the ABNF is not expressive enough to define what a correct OData URL is in every imaginable use case. This specification document defines additional rules that a correct OData URL MUST fulfill. In case of doubt on what makes an OData URL correct the rules defined in this specification document take precedence. Note also that the rules in [OData-ABNF] assume that URLs and URL parts have been percent-encoding normalized as described in section 6.2.2.2 of [RFC3986] before applying the grammar to them, i.e. all characters in the unreserved set (see rule unreserved in  [OData-ABNF]) are plain literals and not percent-encoded. For characters outside of the unreserved set that are significant to OData the ABNF rules explicitly state whether the percent-encoded representation is treated identical to the plain literal representation. This is done to make the input strings in the ABNF test cases more readable.

For example, one of these rules is that single quotes within string literals are represented as two consecutive single quotes.

Example 3: valid OData URLs:

http://host/service/People('O''Neil')

http://host/service/People(%27O%27%27Neil%27) 

http://host/service/People%28%27O%27%27Neil%27%29

http://host/service/Categories('Smartphone%2FTablet')

Example 4: invalid OData URLs:

http://host/service/People('O'Neil') 

http://host/service/People('O%27Neil') 

http://host/service/Categories('Smartphone/Tablet') 

The first and second examples are invalid because a single quote in a string literal must be represented as two consecutive single quotes. The third example is invalid because forward slashes are interpreted as path segment separators and Categories('Smartphone is not a valid OData path segment, nor is Tablet').

3     Service Root URL

The service root URL identifies the root of an OData service. A GET request to this URL returns the format-specific service document, see [OData-JSON].

The service root URL MUST terminate in a forward slash.

The service document enables simple hypermedia-driven clients to enumerate and explore the resources published by the OData service.

4     Resource Path

The rules for resource path construction as defined in this section are optional. OData services SHOULD follow the subsequently described URL path construction rules and are indeed encouraged to do so; as such consistency promotes a rich ecosystem of reusable client components and libraries.

Services that do not follow the resource path conventions for entity container children are strongly encouraged to document their resource paths by annotating entity container children with the term Core.ResourcePath defined in [OData-VocCore]. The annotation value is the URL of the annotated resource and may be relative to xml:base (if present), otherwise the request URL.

Resources exposed by an OData service are addressable by corresponding resource path URL components to enable interaction of the client with that resource aspect.

To illustrate the concept, some examples for resources might be: customers, a single customer, orders related to a single customer, and so forth. Examples of addressable aspects of these resources as exposed by the data model might be: collections of entities, a single entity, properties, links, operations, and so on.

An OData service MAY respond with 301 Moved Permanently or 307 Temporary Redirect from the canonical URL to the actual URL.

4.1 Addressing the Model for a Service

OData services expose their entity model according to [OData-CSDLJSON] or [OData-CSDLXML] at the metadata URL, formed by appending $metadata to the service root URL.

Example 5: Metadata document URL

http://host/service/$metadata

OData clients may request a particular format for metadata either through the Accept header or by using the $format system query option.

Example 6: Metadata document URL with specified format

http://host/service/$metadata?$format=json

4.2 Addressing the Batch Endpoint for a Service

OData services that support batch requests expose a batch URL formed by appending $batch to the service root URL.

Example 7: batch URL

http://host/service/$batch

4.3 Addressing Entities

The basic rules for addressing a collection (of entities), a single entity within a collection, a singleton, as well as a property of an entity are covered in the resourcePath syntax rule in [OData-ABNF].

Below is a (non-normative) snippet from [OData-ABNF]:

resourcePath = entitySetName                  [collectionNavigation]
             / singleton                      [singleNavigation]
             / actionImportCall
             / entityColFunctionImportCall    [ collectionNavigation ]
             / entityFunctionImportCall       [ singleNavigation ]
             / complexColFunctionImportCall   [ collectionPath ]
             / complexFunctionImportCall      [ complexPath ]
             / primitiveColFunctionImportCall [ collectionPath ]
             / primitiveFunctionImportCall    [ singlePath ]
             / functionImportCallNoParens
             / crossjoin
             / '$all'                  [ "/" qualifiedEntityTypeName ]

Since OData has a uniform composable URL syntax and associated rules there are many ways to address a collection of entities, including, but not limited to:

·       Via an entity set (see rule entitySetName in [OData-ABNF])

Example 8:

http://host/service/Products

·       By navigating a collection-valued navigation property (see rule: entityColNavigationProperty)

·       By invoking a function that returns a collection of entities (see rule: entityColFunctionCall)

Example 9: function with parameters in resource path

http://host/service/ProductsByCategoryId(categoryId=2)

                Example 10: function with parameters as query options

http://host/service/ProductsByColor(color=@color)?@color='red'

·       By invoking an action that returns a collection of entities (see rule: actionCall)

Likewise there are many ways to address a single entity.

Sometimes a single entity can be accessed directly, for example by:

·       Invoking a function that returns a single entity (see rule: entityFunctionCall)

·       Invoking an action that returns a single entity (see rule: actionCall)

·       Addressing a singleton

Example 11:

http://host/service/BestProductEverCreated

Often however a single entity is accessed by composing more path segments to a resourcePath that identifies a collection of entities, for example by:

·       Using an entity key to select a single entity (see rules: collectionNavigation and keyPredicate)

Example 12:

http://host/service/Categories(1)

·       Invoking an action bound to a collection of entities that returns a single entity (see rule: boundOperation)

·       Invoking an function bound to a collection of entities that returns a single entity (see rule: boundOperation)

Example 13:

http://host/service/Products/Model.MostExpensive()

These rules are recursive, so it is possible to address a single entity via another single entity, a collection via a single entity and even a collection via a collection; examples include, but are not limited to:

·       By following a navigation from a single entity to another related entity (see rule: entityNavigationProperty)

Example 14:

http://host/service/Products(1)/Supplier

·       By invoking a function bound to a single entity that returns a single entity (see rule: boundOperation)

Example 15:

http://host/service/Products(1)/Model.MostRecentOrder()

·       By invoking an action bound to a single entity that returns a single entity (see rule: boundOperation)

·       By following a navigation from a single entity to a related collection of entities (see rule: entityColNavigationProperty)

Example 16:

http://host/service/Categories(1)/Products

·       By invoking a function bound to a single entity that returns a collection of entities (see rule: boundOperation)

Example 17:

http://host/service/Categories(1)/Model.TopTenProducts()

·       By invoking an action bound to a single entity that returns a collection of entities (see rule: boundOperation)

·       By invoking a function bound to a collection of entities that returns a collection of entities (see rule: boundOperation)

Example 18:

http://host/service/Categories(1)/Products/Model.AllOrders()

·       By invoking an action bound to a collection of entities that returns a collection of entities (see rule: boundOperation)

Finally it is possible to compose path segments onto a resource path that identifies a primitive, complex instance, collection of primitives or collection of complex instances and bind an action or function that returns an entity or collections of entities.

4.3.1 Canonical URL

For OData services conformant with the addressing conventions in this section, the canonical form of an absolute URL identifying a non-contained entity is formed by adding a single path segment to the service root URL. The path segment is made up of the name of the entity set associated with the entity followed by the key predicate identifying the entity within the collection. No type-cast segment is added to the canonical URL, even if the entity is an instance of a type derived from the declared entity type of its entity set.

The canonical key predicate for single-part keys consists only of the key property value without the key property name. For multi-part keys the key properties appear in the same order they appear in the key definition in the service metadata.

Example 19: Non-canonical URL

http://host/service/Categories(ID=1)/Products(ID=1)

Example 20: Canonical URL for previous example:

http://host/service/Products(1)

4.3.2 Canonical URL for Contained Entities

For contained entities (i.e. related via a containment navigation property, see [OData-CSDLJSON] or [OData-CSDLXML]) the canonical URL is the canonical URL of the containing entity followed by:

·       A type-cast segment if the navigation property is defined on a type derived from the entity type declared for the entity set,

·       A path segment for the containment navigation property, and

·       If the navigation property returns a collection, a key predicate that uniquely identifies the entity in that collection.

If the containment navigation property is defined on a complex type used within an ordered collection, the canonical URL of the containing entity is the canonical URL for the collection of complex types followed by a segment containing the zero-based ordinal of the complex typed instance within the collection.

4.3.3 URLs for Related Entities with Referential Constraints

If a navigation property leading to a related entity type has a partner navigation property that specifies a referential constraint, then those key properties of the related entity that take part in the referential constraint MAY be omitted from URLs.

Example 21: full key predicate of related entity

https://host/service/Orders(1)/Items(OrderID=1,ItemNo=2)

Example 22: shortened key predicate of related entity

https://host/service/Orders(1)/Items(2)

The two above examples are equivalent if the navigation property Items from Order to OrderItem has a partner navigation property from OrderItem to Order with a referential constraint tying the value of the OrderID key property of the OrderItem to the value of the ID key property of the Order.

The shorter form that does not specify the constrained key parts redundantly is preferred. If the value of the constrained key is redundantly specified, then it MUST match the principal key value.

4.3.4 Resolving an Entity-Id

To resolve an entity-id into a representation of the identified entity, the client issues a GET request to the $entity resource located at the URL $entity relative to the service root URL. The entity-id MUST be specified using the system query option $id. The entity-id may be expressed as an absolute IRI or relative to the request root URL.

Example 23: request the entity representation for an entity-id

http://host/service/$entity?$id=Products(0)

The semantics of $entity are covered in the [OData-Protocol] document.

4.3.5 Alternate Keys

In addition to the canonical (primary) key an entity set or entity type can specify one or more alternate keys with the Core.AlternateKeys term (see [OData-VocCore]). Entities can be addressed via an alternate key using the same parentheses-style convention as for the canonical key, with one difference: single-part alternate keys MUST specify the key property name to unambiguously determine the alternate key.

Example 24: the same employee identified via the alternate key SSN, the canonical (primary) key ID using the non-canonical long form with specified key property name, and the canonical short form without key property name

http://host/service/Employees(SSN='123-45-6789')

http://host/service/Employees(ID='A1245')

http://host/service/Employees('A1245')

4.3.6 Key-as-Segment Convention

Services MAY support an alternate convention for addressing entities by appending a segment containing the unquoted key value to the URL of the collection containing the entity. Forward-slashes in key value segments MUST be percent-encoded; single quotes within key value segments are treated as part of the key value and do not need to be doubled or percent encoded.

Example 25: valid OData URLs:

http://host/service/Employees/A1245

http://host/service/People/O'Neil

http://host/service/People/O%27Neil 

http://host/service/Categories/Smartphone%2FTablet

For multi-part keys, the entity MUST be addressed by multiple segments applied, one for each key value, in the order they appear in the metadata description of the entity key.

Example 26: multi-part key predicate, parentheses-style and key-as-segment

https://host/service/OrderItems(OrderID=1,ItemNo=2)

https://host/service/OrderItems/1/2

If a navigation property leading to a related entity type has a partner navigation property that specifies a referential constraint, then those key properties of the related entity that take part in the referential constraint MUST be omitted from URLs using key-as-segment convention.

Example 27: key predicate of related entity – no key segments for key properties of related entity with a referential constraint to preceding key segments

https://host/service/Orders/1/Items/2

The above example assumes that the navigation property Items from Order to OrderItem has a partner navigation property from OrderItem to Order with a referential constraint tying the value of the OrderID key property of the OrderItem to the value of the ID key property of the Order.

Because representing key values as segments could be ambiguous with other URL construction conventions, services that support key-as segment MUST implement the following precedence rules:

If a segment following an entity collection:

1)    matches a defined OData segment (starting with “$”), treat it as such

2)    matches a qualified bound function, bound action, or type name, treat it as such

3)    matches an unqualified bound function, bound action, or type name defined in a default namespace (see [OData-Protocol]) treat it as such

4)    treat as a key value

For maximum interoperability, services that support the key-as-segment convention SHOULD also support the canonical parentheses-style convention for addressing an entity within a collection, otherwise they MUST specify the URL for each returned entity in a response, as specified by the particular format.

Note: the key-as-segment convention can only be used with the canonical (primary) key and cannot be used with alternate keys as the key property names are not present in the keys and an alternative key cannot be determined.

4.4 Addressing References between Entities

OData services are based on a data model that supports relationships as first class constructs. For example, an OData service could expose a collection of Products entities each of which are related to a Category entity.

References between entities are addressable in OData just like entities themselves are (as described above) by appending a navigation property name followed by /$ref to the entity URL.

Example 28: URL addressing the references between Categories(1) and Products

http://host/service/Categories(1)/Products/$ref

Resource paths addressing a single entity reference can be used in DELETE requests to unrelated two entities. Resource paths addressing collection of references can be used in DELETE requests if they are followed by the system query option $id identifying one of the entity references in the collection. The entity-id specified by $id may be expressed absolute or relative to the request URL. For details see [OData-Protocol].

Example 29: two ways of unrelating Categories(1) and Products(0)

DELETE http://host/service/Categories(1)/Products/$ref?$id=../../Products(0)

DELETE http://host/service/Products(0)/Category/$ref

4.5 Addressing Operations

The semantic rules for addressing and invoking actions and functions are defined in the [OData-Protocol] document.

Services MAY additionally support the use of the unqualified name of an action or function in a URL by defining one or more default namespaces through the Core.DefaultNamespace term defined in [OData-VocCore]. For more information on default namespaces, see Default Namespaces in [OData-Protocol].

4.5.1 Addressing Actions

The grammar for addressing and invoking actions is defined by the following syntax grammar rules in [OData-ABNF]:

·       The actionImportCall syntax rule defines the grammar in the resourcePath for addressing and invoking an action import directly from the service root.

·       The boundActionCall syntax rule defines the grammar in the resourcePath for addressing and invoking an action that is appended to a resourcePath that identifies some resources that can be used as the binding parameter value when invoking the action.

·       The boundOperation syntax rule (which encompasses the boundActionCall syntax rule), when used by the resourcePath syntax rule, illustrates how a boundActionCall can be appended to a resourcePath.

4.5.2 Addressing Functions

The grammar for addressing and invoking functions is defined by a number syntax grammar rules in [OData-ABNF], in particular:

·       The function import call syntax rules complexFunctionImportCall, complexColFunctionImportCall, entityFunctionImportCall, entityColFunctionImportCall, primitiveFunctionImportCall, and primitiveColFunctionImportCall define the grammar in the resourcePath for addressing and providing parameters for a function import directly from the service root.

·       The bound function call syntax rules boundComplexFunctionCall, boundComplexColFunctionCall, boundEntityFunctionCall, boundEntityColFunctionCall, boundPrimitiveFunctionCall and boundPrimitiveColFunctionCall define the grammar in the resourcePath for addressing and providing parameters for a function that is appended to a resourcePath that identifies some resources that can be used as the binding parameter value when invoking the function.

·       The boundOperation syntax rule (which encompasses the bound function call syntax rules), when used by the resourcePath syntax rule, illustrates how a bound function call can be appended to a resourcePath.

·       The functionExpr and boundFunctionExpr syntax rules as used by the filter and orderby syntax rules define the grammar for invoking functions to help filter and order resources identified by the resourcePath of the URL.

·       The aliasAndValue syntax rule defines the grammar for providing function parameter values using Parameter Alias Syntax, see [OData-Protocol].

4.6 Addressing a Property

To address an entity property clients append a path segment containing the property name to the URL of the entity. If the property has a complex type value, properties of that value can be addressed by further property name composition.

4.7 Addressing a Property Value

To address the raw value of a primitive property, clients append the path segment /$value to the property URL.

Properties of type Edm.Stream already return the raw value of the media stream and do not support appending the /$value segment.

4.8 Addressing the Count of a Collection

To address the raw value of the number of items in a collection, clients append /$count to the resource path of the URL identifying the entity set or collection.

The /$count path suffix identifies the integer count of records in the collection and SHOULD NOT be combined with the system query options  $top, $skip, $orderby, $expand, and $format. The count MUST NOT be affected by $top, $skip, $orderby, or $expand.

The count is calculated after applying any /$filter= path segments, or $filter or $search system query options to the collection.

 

Example 30: the number of related entities

http://host/service/Categories(1)/Products/$count

Example 31: the number of entities in an entity set

http://host/service/Products/$count

Example 32: entity count in a $filter expression. Note that the spaces around gt are for readability of the example only; in real URLs they must be percent-encoded as %20.

http://host/service/Categories?$filter=Products/$count gt 0

Example 33: count of a filtered collection in a $filter expression; returns all Categories containing more than two products whose price is greater than 5.00.

http://host/service/Categories?
       $filter=Products/$count($filter=Price gt 5.00)
gt 2

 Example 30: entity count in an $orderby expression

http://host/service/Categories?$orderby=Products/$count

4.9 Addressing a Member within an Entity Collection

Collections of entities are modeled as entity sets, collection-valued navigation properties, or operation results.

For entity sets, results of operations associated with an entity set through an EntitySet or EntitySetPath declaration, or collection-valued navigation properties with a NavigationPropertyBinding or ContainsTarget=true specification, members of the collection can be addressed by convention by appending the parenthesized key to the URL specifying the collection of entities, or by using the key-as-segment convention if supported by the service.

For collection-valued navigation properties with navigation property bindings that end in a type-cast segment, a type-cast segment MUST be appended to the collection URL before appending the key segment.

Note: entity sets or collection-valued navigation properties annotated with term Capabilities.IndexableByKey defined in [OData-VocCap] and a value of false do not support addressing their members by key.

4.10 Addressing a Member of an Ordered Collection

Collections can be annotated as ordered using the Core.Ordered term (see [OData-VocCore]). Individual items within an ordered collection of primitive or complex types can be addressed by appending a segment containing the zero-based ordinal to the URL of the collection. A negative ordinal number indexes from the end of the collection, with -1 representing the last item in the collection. Services MUST NOT specify a negative index when returning the address of a member of an ordered collection.

Entity types are stably addressable using their canonical URL and SHOULD NOT be accessed or accessible using an index.

Example 31: the first address in a list of addresses for MainSupplier

http://host/service/MainSupplier/Addresses/0

4.11 Addressing Derived Types

Any resource path or path expression identifying a collection of entities or complex type instances can be appended with a path segment containing the qualified name of a type derived from the declared type of the collection. The result will be restricted to instances of the derived type and may be empty. 

Any resource path or path expression identifying a single entity or complex type instance can be appended with a path segment containing the qualified name of a type derived from the declared type of the identified resource. If used in a resource path and the identified resource is not an instance of the derived type, the request will result in a 404 Not Found response. If used in a path expression that is part of a Boolean expression, the type cast will evaluate to null

Services MAY additionally support the use of the unqualified name of a derived type in a URL by defining one or more default namespaces through the Core.DefaultNamespace term defined in [OData-VocCore]. For more information on default namespaces, see Default Namespaces in [OData-Protocol].

Services MAY also support treating an instance as a type outside of the type hierarchy using the same syntax and semantics as when addressing a derived type. In this case, the set and values of properties of the addressed type may be different than the properties of the source type. The set of such possible target types outside of the type hierarchy SHOULD be called out using the Core.MayImplement annotation term, defined in [OData-VocCore].

Example 34: entity set restricted to VipCustomer instances

http://host/service/Customers/Model.VipCustomer

Example 35: entity restricted to a VipCustomer instance, resulting in 404 Not Found if the customer with key 1 is not a VipCustomer

http://host/service/Customers/Model.VipCustomer(1)

http://host/service/Customers(1)/Model.VipCustomer

Example 36: cast the complex property Address to its derived type DetailedAddress, then get a property of the derived type

http://host/service/Customers(1)/Address/Model.DetailedAddress/Location

Example 37: filter expression with type cast; will evaluate to null for all non-VipCustomer instances and thus return only instances of VipCustomer

http://host/service/Customers?

       $filter=Model.VipCustomer/PercentageOfVipPromotionProductsOrdered gt 80

Example 38: expand the single related Customer only if it is an instance of Model.VipCustomer. For to-many relationships only Model.VipCustomer instances would be inlined,

http://host/service/Orders?$expand=Customer/Model.VipCustomer

4.12 Addressing a Subset of a Collection

Any resource path or path expression identifying a collection can be appended with a filter path segment consisting of $filter= followed by a parameter alias. A filter expression following the filter syntax rule in [OData-ABNF] MUST be assigned to the parameter alias in the query part of the request URL. The collection will be restricted to instances matching the filter expression assigned to the parameter alias and may be empty. 

The $filter= path segment MAY occur multiple times and it MAY be combined with the $filter system query option.

Example 39: red products that cost less than 10  – combining path segment and system query option

GET Products/$filter=@foo?@foo=Price lt 10&$filter=Color eq 'red'

Example 40: red products that cost less than 10 – combine two path segments

GET Products/$filter=@p/$filter=c?@p=Price lt 10&@c=Color eq 'red'

Note that the $filter= path segment filters the “input” to the operation, and the $filter system query option filters the result of the operation, so the two can be used interchangeably only for GET operations. For a PATCH operation, the $filter= path segment is evaluated on the items before the modification and determines which items are to be modified, whereas the $filter system query option is evaluated after the modification and determines which of the modified items are part of the response.

The $filter= path segment MAY be followed by a path segment identifying a bound action or bound function applicable to the collection.

Example 41: invoke the Special.Cluster action on all products older than 3

POST /service/Products/$filter=@foo/Special.Cluster?@foo=Age gt 3

4.13 Addressing Each Member of a Collection

To apply a PATCH or DELETE request to each member of a collection, clients append the path segment /$each to a resource path identifying a collection.

To apply a bound action or function to each member of a collection, clients append the path segment /$each followed by a path segment identifying the bound action or function. The response is a collection of instances of the result type of the bound operation. If the bound operation returns a collection, the response is a collection of collections. System query options applied to the response can use $it to reference an item in the outermost collection, followed by /any, /all, or /$count

The resource path of the collection preceding /$each MAY contain type-cast or filter segments to subset the collection.

4.14 Addressing the Media Stream of a Media Entity

To address the media stream represented by a media entity, clients append /$value to the resource path of the media entity URL. Services may redirect from this canonical URL to the source URL of the media stream.

Example 42: request the media stream for the picture with the key value Sunset4321299432:

http://host/service/Pictures('Sunset4321299432')/$value

4.15 Addressing the Cross Join of Entity Sets

In addition to querying related entities through navigation properties defined in the entity model of a service, the cross join operator allows querying across unrelated entity sets.

The cross join is addressed by appending the path segment $crossjoin to the service root URL, followed by the parenthesized comma-separated list of joined entity sets. It returns the Cartesian product of all the specified entity sets, represented as a collection of instances of a virtual complex type. Each instance consists of one non-nullable, single-valued navigation property per joined entity set. Each such navigation property is named identical to the corresponding entity set, with a target type equal to the declared entity type of the corresponding entity set.

The $filter and $orderby query options can be specified using properties of the entities in the selected entity sets, prepended with the entity set as the navigation property name.

The $expand query option can be specified using the names of the selected entity sets as navigation property names. If a selected entity set is not expanded, it MUST be represented using the read URL of the related entity as a navigation link in the complex type instance.

The $count, $skip, and $top query options can also be used with no special semantics.

Example 43: if Sales had a structural property ProductID instead of a navigation property Product, a “cross join” between Sales and Products could be addressed

http://host/service/$crossjoin(Products,Sales)?
                                        $filter=Products/ID eq Sales/ProductID                

and would result in

{
  "@odata.context":"http://host/service/$metadata#Collection(Edm.ComplexType)",
  "value":[
    {
      "Products@odata.navigationLink":"Products(0)",
      "Sales@odata.navigationLink":"Sales(42)",
    },
    {
      "Products@odata.navigationLink":"Products(0)",
      "Sales@odata.navigationLink":"Sales(57)",
    },
    ...
    {
      "Products@odata.navigationLink":"Products(99)",
      "Sales@odata.navigationLink":"Sales(21)",
    }
  ]

}

4.16 Addressing All Entities in a Service

The symbolic resource $all, located at the service root, identifies the collection of all entities in a service, i.e. the union of all entity sets plus all singletons.

This symbolic resource is of type Collection(Edm.EntityType) and allows the $search system query option plus all other query options applicable to collections of entities.

The $all resource can be appended with a path segment containing the qualified name of an entity type in order to restrict the collections to entities of that type. Query options such as $select, $filter, $expand and $orderby can be applied to this restricted set according to the specified type.

Example 44: all entities in a service that somehow match red

http://host/service/$all?$search=red

Example 45: all Customer entities in a service whose name contains red

http://host/service/$all/Model.Customer?$filter=contains(Name,'red')

5     Query Options

The query options part of an OData URL specifies three types of information: system query options, custom query options, and parameter aliases. All OData services MUST follow the query string parsing and construction rules defined in this section and its subsections.

5.1 System Query Options

System query options are query string parameters that control the amount and order of the data returned for the resource identified by the URL. The names of all system query options are optionally prefixed with a dollar ($) character. 4.01 Services MUST support case-insensitive system query option names specified with or without the $ prefix. Clients that want to work with 4.0 services MUST use lower case names and specify the $ prefix.

For GET, PATCH, and PUT requests the following rules apply:

·       Resource paths identifying a single entity, a complex type instance, a collection of entities, or a collection of complex type instances allow $compute, $expand and $select.

·       Resource paths identifying a collection allow $filter, $search, $count, $orderby, $skip, and $top.

·       Resource paths ending in /$count allow $filter and $search.

·       Resource paths not ending in /$count or /$batch allow $format.

For POST requests to an action URL the return type of the action determines the applicable system query options that a service MAY support, following the same rules as GET requests.

POST requests to an entity set follow the same rules as GET requests that return a single entity.

System query options SHOULD NOT be applied to a DELETE request.

An OData service may support some or all of the system query options defined. If a data service does not support a system query option, it MUST reject any request that contains the unsupported option.

The same system query option, irrespective of casing of whether or not it is prefixed with a $, MUST NOT be specified more than once for any resource.

The semantics of all system query options are defined in the [OData-Protocol] document.

The grammar and syntax rules for system query options are defined in [OData-ABNF].

Dynamic properties can be used in the same way as declared properties. If they are not defined on an instance, they evaluate to null.

5.1.1 System Query Option $filter

The $filter system query option allows clients to filter a collection of resources that are addressed by a request URL. The expression specified with $filter is evaluated for each resource in the collection, and only items where the expression evaluates to true are included in the response. Resources for which the expression evaluates to false or to null, or which reference properties that are unavailable due to permissions, are omitted from the response.

The [OData-ABNF] filter syntax rule defines the formal grammar of the $filter query option.

5.1.1.1 Logical Operators

OData defines a set of logical operators that evaluate to true or false (i.e. a boolCommonExpr as defined in [OData-ABNF]). Logical operators are typically used to filter a collection of resources.

The syntax rules for the logical operators are defined in [OData-ABNF].  4.01 Services MUST support case-insensitive operator names. Clients that want to work with 4.0 services MUST use lower case operator names.

The six comparison operators can be used with all primitive values except Edm.Binary, Edm.Stream, and the Edm.Geo types. Edm.Binary, Edm.Stream, and the Edm.Geo types can only be compared to the null value using the eq and ne operators.

When applied to operands of numeric types, numeric promotion rules are applied.

The eq, ne, and in operators can be used with collection-valued operands, and the eq and ne operators can be used with structured operands.

5.1.1.1.1 Equals

The eq operator returns true if the left operand is equal to the right operand, otherwise it returns false.

When applied to operands of entity types, the eq operator returns true if both operands represent the same entity, or both operands represent null.

When applied to operands of complex types, the eq operator returns true if both operands have the same structure and same values, or both operands represent null.

When applied to ordered collections, the eq operator returns true if both operands have the same cardinality and each member of the left operand is equal to the corresponding member of the right operand.

For services that support comparing unordered collections, the eq operator returns true if both operands are equal after applying the same ordering on both collections.

Each of the special values null, -INF, and INF is equal to itself, and only to itself.

The special value NaN is not equal to anything, even to itself.

5.1.1.1.2 Not Equals

The ne operator returns true if the left operand is not equal to the right operand, otherwise it returns false.

When applied to operands of entity types, the ne operator returns true if the two operands do not represent the same entity.

When applied to operands of complex types, the ne operator returns true if the operands do not have the same structure and same values.

When applied to ordered collections, the ne operator returns true if both operands do not have the same cardinality or any member of the left operand is not equal to the corresponding member of the right operand.

For services that support comparing unordered collections, the ne operator returns true if both operands do not have the same cardinality or do not contain the same members, in any order.

Each of the special values null, -INF, and INF is not equal to any value but itself.

The special value NaN is not equal to anything, even to itself.

The null value is not equal to any value but itself.

5.1.1.1.3 Greater Than

The gt operator returns true if the left operand is greater than the right operand, otherwise it returns false.

The special value INF is greater than any number, and any number is greater than -INF.

The Boolean value true is greater than false.

If any operand is null, the operator returns false.

5.1.1.1.4 Greater Than or Equal

The ge operator returns true if the left operand is greater than or equal to the right operand, otherwise it returns false.

See rules for gt and eq for details.

5.1.1.1.5 Less Than

The lt operator returns true if the left operand is less than the right operand, otherwise it returns false.

The special value -INF is less than any number, and any number is less than INF.

The Boolean value false is less than true.

If any operand is null, the operator returns false.

5.1.1.1.6 Less Than or Equal

The le operator returns true if the left operand is less than or equal to the right operand, otherwise it returns false.

See rules for lt and eq for details.

5.1.1.1.7 And

The and operator returns true if both the left and right operands evaluate to true, otherwise it returns false.

The null value is treated as unknown, so if one operand evaluates to null and the other operand to false, the and operator returns false. All other combinations with null return null.

5.1.1.1.8 Or

The or operator returns false if both the left and right operands both evaluate to false, otherwise it returns true.

The null value is treated as unknown, so if one operand evaluates to null and the other operand to true, the or operator returns true. All other combinations with null return null.

5.1.1.1.9 Not

The not operator returns true if the operand returns false, otherwise it returns false.

The null value is treated as unknown, so not null returns null.

5.1.1.1.10 Has

The has operator returns true if the right operand is an enumeration value whose flag(s) are set on the left operand.

The null value is treated as unknown, so if one operand evaluates to null, the has operator returns null.

5.1.1.1.11 In

The in operator returns true if the left operand is a member of the right operand. The right operand MUST be either a comma-separated list of primitive values, enclosed in parentheses, or a single expression that resolves to a collection.

5.1.1.1.12 Logical Operator Examples

The following examples illustrate the use and semantics of each of the logical operators.

Example 46: all products with a Name equal to 'Milk'

http://host/service/Products?$filter=Name eq 'Milk'

Example 47: all products with a Name not equal to 'Milk'

http://host/service/Products?$filter=Name ne 'Milk'

Example 48: all products with a Name greater than 'Milk':

http://host/service/Products?$filter=Name gt 'Milk'

Example 49: all products with a Name greater than or equal to 'Milk':

http://host/service/Products?$filter=Name ge 'Milk'

Example 50: all products with a Name less than 'Milk':

http://host/service/Products?$filter=Name lt 'Milk'

Example 51: all products with a Name less than or equal to 'Milk':

http://host/service/Products?$filter=Name le 'Milk'

Example 52: all products with the Name 'Milk' that also have a Price less than 2.55:

http://host/service/Products?$filter=Name eq 'Milk' and Price lt 2.55

Example 53: all products that either have the Name 'Milk' or have a Price less than 2.55:

http://host/service/Products?$filter=Name eq 'Milk' or Price lt 2.55

Example 54: all products that do not have a Name that ends with 'ilk':

http://host/service/Products?$filter=not endswith(Name,'ilk')

Example 55: all products whose style value includes Yellow:

http://host/service/Products?$filter=style has Sales.Pattern'Yellow'

Example 56: all products whose name value is ‘Milk’ or ‘Cheese’:

http://host/service/Products?$filter=Name in ('Milk', 'Cheese')

5.1.1.2 Arithmetic Operators

OData defines a set of arithmetic operators that require operands that evaluate to numeric types. Arithmetic operators are typically used to filter a collection of resources. However, services MAY allow using arithmetic operators with the $orderby system query option.

If an operand of an arithmetic operator is null, the result is null.

The syntax rules for the arithmetic operators are defined in [OData-ABNF]. 4.01 Services MUST support case-insensitive operator names. Clients that want to work with 4.0 services MUST use lower case operator names.

5.1.1.2.1 Addition

The add operator adds the left and right numeric operands.

For operands of type Edm.Decimal the scale of the result is scaleof(A add B) = max(scaleof(A), scaleof(B)), or variable if any operand has variable scale.

The add operator is also valid for the following time-related operands:

·       DateTimeOffset add Duration results in a DateTimeOffset 

·       Duration add Duration results in a Duration 

·       Date add Duration results in a Date

The rules for time-related operands are defined in [XML‑Schema‑2], section E.3.3. Specifically, for adding a duration to a date:

·       Convert date to datetime (in any timezone) with a zero time component

·       Add/subtract duration

·       Convert to date by removing the time and timezone components

Thus today plus a positive duration smaller than one day is today; today minus a positive duration smaller than one day is yesterday.

5.1.1.2.2 Subtraction

The sub operator subtracts the right numeric operand from the left numeric operand.

For operands of type Edm.Decimal the scale of the result is scaleof(A sub B) = max(scaleof(A), scaleof(B)), or variable if any operand has variable scale.

The sub operator is also valid for the following time-related operands:

·       DateTimeOffset sub Duration results in a DateTimeOffset 

·       Duration sub Duration results in a Duration 

·       DateTimeOffset sub DateTimeOffset results in a Duration 

·       Date sub Duration results in a Date

·       Date sub Date results in a Duration 

The rules for time-related operands are defined in [XML‑Schema‑2], section E.3.3. Specifically for subtracting a duration from a date see the preceding section.

5.1.1.2.3 Negation

The negation operator, represented by a minus (-) sign, changes the sign of its numeric or Duration operand.

5.1.1.2.4 Multiplication

The mul operator multiplies the left and right numeric operands. The mul operator is also valid for multiplying a Duration value with a numeric value.

For operands of type Edm.Decimal the scale of the result is scaleof(A mul B) = scaleof(A) + scaleof(B), floating if any operand has floating scale, or else variable if any operand has variable scale.

5.1.1.2.5 Division

The div and divby operators divide the left numeric operand by the right numeric operand. They are also valid for dividing a Duration value by a numeric value.

If the left operand is of type Edm.Decimal with floating scale, Edm.Double, or Edm.Single, then positive div zero returns INF, negative div zero returns -INF, and zero div zero returns NaN. For all other types the request fails.

For operands of type Edm.Decimal the result is computed with maximal decimal scale. If any operand has floating scale, the result has floating scale, else if any operand has variable scale, the result has variable scale. Otherwise the resulting scale is service-specific, and clients can use cast to force the result to a specific scale.

The div and divby operators differ in their handling of integers. If both operands to div are of an integer type, the result is an integer representing the whole number of times the right operator fits into the left operator. The divby operator, on the other hand, promotes both operands to decimal before computing the result, may yield a fractional result, and does not fail for divby zero, returning -INF, INF, or NaN depending on the sign of the left operand.

5.1.1.2.6 Modulo

The mod operator returns the remainder when the left numeric operand is divided by the right numeric operand.  The sign of the result is the same as the sign of the left operand. If the right operand is zero, the request fails.

For operands of type Edm.Decimal the scale of the result is scaleof(A mod B) = max(scaleof(A), scaleof(B)), or variable if any operand has variable scale.

5.1.1.2.7 Arithmetic Operator Examples

The following examples illustrate the use and semantics of each of the Arithmetic operators.

Example 57: all products with a Price of 2.55:

http://host/service/Products?$filter=Price add 2.45 eq 5.00

Example 58: all products with a Price of 2.55:

http://host/service/Products?$filter=Price sub 0.55 eq 2.00

Example 59: all products with a Price of 2.55:

http://host/service/Products?$filter=Price mul 2.0 eq 5.10

Example 60: all products with a Price of 2.55:

http://host/service/Products?$filter=Price div 2.55 eq 1

Example 61: all products with an integer Rating value of 4 or 5:

http://host/service/Products?$filter=Rating div 2 eq 2

Example 62: all products with an integer Rating value of 5:

http://host/service/Products?$filter=Rating divby 2 eq 2.5

Example 63: all products with a Rating exactly divisible by 5:

http://host/service/Products?$filter=Rating mod 5 eq 0

5.1.1.3 Grouping

The Grouping operator (open and close parenthesis “( )”) controls the evaluation order of an expression. The Grouping operator returns the expression grouped inside the parenthesis.

Example 64: all products because 9 mod 3 is 0

http://host/service/Products?$filter=(4 add 5) mod (4 sub 1) eq 0

5.1.1.4 Canonical Functions

In addition to operators, a set of functions is also defined for use with the $filter or $orderby system query options. The following sections describe the available functions. Note: ISNULL or COALESCE operators are not defined. Instead, OData defines a null literal that can be used in comparisons.

If a parameter of a canonical function is null, the function returns null.

The syntax rules for all functions are defined in [OData-ABNF]. 4.01 Services MUST support case-insensitive canonical function names. Clients that want to work with 4.0 services MUST use lower case canonical function names.

5.1.1.5 String and Collection Functions

5.1.1.5.1 concat

The concat function has three overloads, with the following signatures:

Edm.String concat(Edm.String,Edm.String)
Collection concat(Collection,Collection)
OrderedCollection concat(OrderedCollection,OrderedCollection)

The concat function with string parameter values returns a string that appends the second parameter string value to the first.

The concat function with collection parameter values returns a collection that appends all items of the second collection to the first. If both collections are ordered, the result is also ordered.

The concatMethodCallExpr syntax rule defines how the concat function is invoked.

Example 65: all customers from Berlin, Germany

http://host/service/Customers?

                $filter=concat(concat(City,', '), Country) eq 'Berlin, Germany'

5.1.1.5.2 contains

The contains function has two overloads, with the following signatures:

Edm.Boolean contains(Edm.String,Edm.String)
Edm.Boolean contains(OrderedCollection,OrderedCollection)

The contains function with string parameter values returns true if the second string is a substring of the first string, otherwise it returns false.

The contains function with ordered collection parameter values returns true if the first collection can be transformed into the second collection by removing zero or more items from the beginning or the end of the first collection.

The containsMethodCallExpr syntax rule defines how the contains function is invoked.

Example 66: all customers with a CompanyName that contains 'Alfreds'

http://host/service/Customers?$filter=contains(CompanyName,'Alfreds')

5.1.1.5.3 endswith

The endswith function has two overloads, with the following signatures:

Edm.Boolean endswith(Edm.String,Edm.String)
Edm.Boolean endswith(OrderedCollection,OrderedCollection)

The endswith function with string parameter values returns true if the first string ends with the second string, otherwise it returns false.

The endswith function with ordered collection parameter values returns true if the first collection can be transformed into the second collection by removing zero or more items from the beginning of the first collection.

The endsWithMethodCallExpr syntax rule defines how the endswith function is invoked.

Example 67: all customers with a CompanyName that ends with 'Futterkiste'

http://host/service/Customers?$filter=endswith(CompanyName,'Futterkiste')

5.1.1.5.4 indexof

The indexof function has two overloads, with the following signatures:

Edm.Int32 indexof(Edm.String,Edm.String)
Edm.Int32 indexof(OrderedCollection,OrderedCollection)

The indexof function with string parameter values returns the zero-based character position of the first occurrence of the second string in the first string, or -1 if the first string does not contain the second string.

The indexof function with ordered collection parameter values returns the zero-based index of the first occurrence of the second collection in the first collection, or -1 if the first collection does not contain the second collection.

The indexOfMethodCallExpr syntax rule defines how the indexof function is invoked.

Example 68: all customers with a CompanyName containing 'lfreds' starting at the second character

http://host/service/Customers?$filter=indexof(CompanyName,'lfreds') eq 1

5.1.1.5.5 length

The length function has two overloads, with the following signatures:

Edm.Int32 length(Edm.String)
Edm.Int32 length(Collection)

The length function with a string parameter value returns the number of characters in the string.

The length function with a collection parameter value returns the number of itens in the collection.

The lengthMethodCallExpr syntax rule defines how the length function is invoked.

Example 69: all customers with a CompanyName that is 19 characters long

http://host/service/Customers?$filter=length(CompanyName) eq 19

5.1.1.5.6 startswith

The startswith function has two overloads, with the following signatures:

Edm.Boolean startswith(Edm.String,Edm.String)
Edm.Boolean startswith(Collection,Collection)

The startswith function with string parameter values returns true if the first string starts with the second string, otherwise it returns false.

The startswith function with ordered collection parameter values returns true if the first collection can be transformed into the second collection by removing zero or more items from the end of the first collection.

The startsWithMethodCallExpr syntax rule defines how the startswith function is invoked.

Example 70: all customers with a CompanyName that starts with 'Alfr'

http://host/service/Customers?$filter=startswith(CompanyName,'Alfr')

5.1.1.5.7 substring

The substring function has four overloads, with the following signatures:

Edm.String substring(Edm.String,Edm.Int32)
Edm.String substring(Edm.String,Edm.Int32,Edm.Int32)
OrderedCollection substring(OrderedCollection,Edm.Int32)
OrderedCollection substring(OrderedCollection,Edm.Int32,Edm.Int32)

The two-argument substring function with string parameter values returns a substring of the first parameter string value, starting at the Nth character and finishing at the last character (where N is the second parameter integer value). The three-argument substring function with string parameter values returns a substring of the first parameter string value identified by selecting up to M characters starting at the Nth character (where N is the second parameter integer value and M is the third parameter integer value).

The two-argument substring function with ordered collection parameter values returns an ordered collection consisting of all items of the first collection starting at the Nth item and finishing at the last item. The three-argument substring function with ordered collection parameter values returns an ordered collection consisting of up to M items of the first collection starting at the Nth item (where N is the second parameter integer value and M is the third parameter integer value).

The start index N is zero-based.

If the start index N is larger than the length of the string/collection, an empty string/collection is returned.

If the length M is larger than the length of the remaining string/collection starting at the Nth character/item, as many characters/items as are available are returned.

A negative length M is a bad request.

A negative start index N, if supported, returns a string/collection starting N characters/items before the end of the string/collection.

The substringMethodCallExpr syntax rule defines how the substring function is invoked.

Example 71: all customers with a CompanyName of 'lfreds Futterkiste' once the first character has been removed

http://host/service/Customers?
                      $filter=substring(CompanyName, 1) eq 'lfreds Futterkiste'

Example 72: all customers with a CompanyName that has 'lf' as the second and third characters, e.g, 'Alfreds Futterkiste'

http://host/service/Customers?$filter=substring(CompanyName,1,2) eq 'lf'

5.1.1.6 Collection Functions

5.1.1.6.1 hassubset

The hassubset function has the following signature:

Edm.Boolean hassubset(Collection, Collection)

The hassubset function returns true if the first collection can be transformed into the second collection by reordering and/or removing zero or more items. The hasSubsetMethodCallExpr syntax rule defines how the hassubset function is invoked.

Example 73: hassubset expressions that return true

hassubset([4,1,3],[4,1,3])

hassubset([4,1,3],[1,3,4])

hassubset([4,1,3],[3,1])

hassubset([4,1,3],[4,3])

hassubset([4,1,3,1],[1,1])

Example 74: hassubset expression that returns false: 1 appears only once in the left operand

hassubset([1,2],[1,1,2])

5.1.1.6.2 hassubsequence

The hassubsequence function has the following signature:

Edm.Boolean hassubsequence(OrderedCollection,OrderedCollection)

The hassubsequence function returns true if the first collection can be transformed into the second collection by removing zero or more items. The hasSubsequenceMethodCallExpr syntax rule defines how the hassubsequence function is invoked.

Example 75: hassubsequence expressions that return true

hassubsequence([4,1,3],[4,1,3])

hassubsequence([4,1,3],[4,1])

hassubsequence([4,1,3],[4,3])

hassubsequence([4,1,3,1],[1,1])

Example 76: hassubsequence expressions that return false

hassubsequence([4,1,3],[1,3,4])

hassubsequence([4,1,3],[3,1])

hassubsequence([1,2],[1,1,2])

5.1.1.7 String Functions

5.1.1.7.1 tolower

The tolower function has the following signature:

Edm.String tolower(Edm.String)

The tolower function returns the input parameter string value with all uppercase characters converted to lowercase according to Unicode rules. The toLowerMethodCallExpr syntax rule defines how the tolower function is invoked.

Example 77: all customers with a CompanyName that equals 'alfreds futterkiste' once any uppercase characters have been converted to lowercase

http://host/service/Customers?

                          $filter=tolower(CompanyName) eq 'alfreds futterkiste'

5.1.1.7.2 toupper

The toupper function has the following signature:

Edm.String toupper(Edm.String)

The toupper function returns the input parameter string value with all lowercase characters converted to uppercase according to Unicode rules. The toUpperMethodCallExpr syntax rule defines how the toupper function is invoked.

Example 78: all customers with a CompanyName that equals 'ALFREDS FUTTERKISTE' once any lowercase characters have been converted to uppercase

http://host/service/Customers?

                          $filter=toupper(CompanyName) eq 'ALFREDS FUTTERKISTE'

5.1.1.7.3 trim

The trim function has the following signature:

Edm.String trim(Edm.String)

The trim function returns the input parameter string value with all leading and trailing whitespace characters, according to Unicode rules, removed. The trimMethodCallExpr syntax rule defines how the trim function is invoked.

Example 79: all customers with a CompanyName without leading or trailing whitespace characters

http://host/service/Customers?$filter=trim(CompanyName) eq CompanyName

5.1.1.8 Date and Time Functions

5.1.1.8.1 date

The date function has the following signature:

Edm.Date date(Edm.DateTimeOffset)

The date function returns the date part of the DateTimeOffset parameter value, evaluated in the time zone of the DateTimeOffset parameter value.

5.1.1.8.2 day

The day function has the following signatures:

Edm.Int32 day(Edm.Date)
Edm.Int32 day(Edm.DateTimeOffset)

The day function returns the day component Date or DateTimeOffset parameter value, evaluated in the time zone of the DateTimeOffset parameter value. The dayMethodCallExpr syntax rule defines how the day function is invoked.

Services that are unable to preserve the offset of Edm.DateTimeOffset values and instead normalize the values to some common time zone (i.e. UTC) MUST fail evaluation of the day function for literal Edm.DateTimeOffset values that are not stated in the time zone of the normalized values.

Example 80: all employees born on the 8th day of a month

http://host/service/Employees?$filter=day(BirthDate) eq 8

5.1.1.8.3 fractionalseconds

The fractionalseconds function has the following signatures:

Edm.Decimal fractionalseconds(Edm.DateTimeOffset)
Edm.Decimal fractionalseconds(Edm.TimeOfDay)

The fractionalseconds function returns the fractional seconds component of the DateTimeOffset or TimeOfDay parameter value as a non-negative decimal value less than 1. The fractionalsecondsMethodCallExpr syntax rule defines how the fractionalseconds function is invoked.

Example 81: all employees born less than 100 milliseconds after a full second of any minute of any hour on any day

http://host/service/Employees?$filter=fractionalseconds(BirthDate) lt 0.1

5.1.1.8.4 hour

The hour function has the following signatures:

Edm.Int32 hour(Edm.DateTimeOffset)
Edm.Int32 hour(Edm.TimeOfDay)

The hour function returns the hour component of the DateTimeOffset or TimeOfDay parameter value, evaluated in the time zone of the DateTimeOffset parameter value. The hourMethodCallExpr syntax rule defines how the hour function is invoked.

Services that are unable to preserve the offset of Edm.DateTimeOffset values and instead normalize the values to some common time zone (i.e. UTC) MUST fail evaluation of the hour function for literal Edm.DateTimeOffset values that are not stated in the time zone of the normalized values.

Example 82: all employees born in the 4th hour of a day

http://host/service/Employees?$filter=hour(BirthDate) eq 4

5.1.1.8.5 maxdatetime

The maxdatetime function has the following signature:

Edm.DateTimeOffset maxdatetime()

The maxdatetime function returns the latest possible point in time as a DateTimeOffset value.

5.1.1.8.6 mindatetime

The mindatetime function has the following signature:

Edm.DateTimeOffset mindatetime()

The mindatetime function returns the earliest possible point in time as a DateTimeOffset value.

5.1.1.8.7 minute

The minute function has the following signatures:

Edm.Int32 minute(Edm.DateTimeOffset)
Edm.Int32 minute(Edm.TimeOfDay)

The minute function returns the minute component of the DateTimeOffset or TimeOfDay parameter value, evaluated in the time zone of the DateTimeOffset parameter value. The minuteMethodCallExpr syntax rule defines how the minute function is invoked.

Example 83: all employees born in the 40th minute of any hour on any day

http://host/service/Employees?$filter=minute(BirthDate) eq 40

5.1.1.8.8 month

The month function has the following signatures:

Edm.Int32 month(Edm.Date)
Edm.Int32 month(Edm.DateTimeOffset)

The month function returns the month component of the Date or DateTimeOffset parameter value, evaluated in the time zone of the DateTimeOffset parameter value. The monthMethodCallExpr syntax rule defines how the month function is invoked.

Services that are unable to preserve the offset of Edm.DateTimeOffset values and instead normalize the values to some common time zone (i.e. UTC) MUST fail evaluation of the month function for literal Edm.DateTimeOffset values that are not stated in the time zone of the normalized values.

Example 84: all employees born in May

http://host/service/Employees?$filter=month(BirthDate) eq 5

5.1.1.8.9 now

The now function has the following signature:

Edm.DateTimeOffset now()

The now function returns the current point in time (date and time with time zone) as a DateTimeOffset value.

Services are free to choose the time zone for the current point, e.g. UTC. Services that are unable to preserve the offset of Edm.DateTimeOffset values and instead normalize the values to some common time zone SHOULD return a value in the normalized time zone (i.e., UTC).

5.1.1.8.10 second

The second function has the following signatures:

Edm.Int32 second(Edm.DateTimeOffset)
Edm.Int32 second(Edm.TimeOfDay)

The second function returns the second component (without the fractional part) of the DateTimeOffset or TimeOfDay parameter value. The secondMethodCallExpr syntax rule defines how the second function is invoked.

Example 85: all employees born in the 40th second of any minute of any hour on any day

http://host/service/Employees?$filter=second(BirthDate) eq 40

5.1.1.8.11 time

The time function has the following signature:

Edm.TimeOfDay time(Edm.DateTimeOffset)

The time function returns the time part of the DateTimeOffset parameter value, evaluated in the time zone of the DateTimeOffset parameter value.

Services that are unable to preserve the offset of Edm.DateTimeOffset values and instead normalize the values to some common time zone (i.e. UTC) MUST fail evaluation of the time function for literal Edm.DateTimeOffset values that are not stated in the time zone of the normalized values.

5.1.1.8.12 totaloffsetminutes

The totaloffsetminutes function has the following signature:

Edm.Int32 totaloffsetminutes(Edm.DateTimeOffset)

The totaloffsetminutes function returns the signed number of minutes in the time zone offset part of the DateTimeOffset parameter value, evaluated in the time zone of the DateTimeOffset parameter value.

5.1.1.8.13 totalseconds

The totalseconds function has the following signature:

Edm.Decimal totalseconds(Edm.Duration)

The totalseconds function returns the duration of the value in total seconds, including fractional seconds.

5.1.1.8.14 year

The year function has the following signatures:

Edm.Int32 year(Edm.Date)
Edm.Int32 year(Edm.DateTimeOffset)

The year function returns the year component of the Date or DateTimeOffset parameter value, evaluated in the time zone of the DateTimeOffset parameter value. The yearMethodCallExpr syntax rule defines how the year function is invoked.

Services that are unable to preserve the offset of Edm.DateTimeOffset values and instead normalize the values to some common time zone (i.e. UTC) MUST fail evaluation of the year function for literal Edm.DateTimeOffset values that are not stated in the time zone of the normalized values.

Example 86: all employees born in 1971

http://host/service/Employees?$filter=year(BirthDate) eq 1971

5.1.1.9 Arithmetic Functions

5.1.1.9.1 ceiling

The ceiling function has the following signatures

Edm.Double ceiling(Edm.Double)
Edm.Decimal ceiling(Edm.Decimal)

The ceiling function rounds the input numeric parameter up to the nearest numeric value with no decimal component. The ceilingMethodCallExpr syntax rule defines how the ceiling function is invoked.

Example 87: all orders with freight costs that round up to 32

http://host/service/Orders?$filter=ceiling(Freight) eq 32

5.1.1.9.2 floor

The floor function has the following signatures

Edm.Double floor(Edm.Double)
Edm.Decimal floor(Edm.Decimal)

The floor function rounds the input numeric parameter down to the nearest numeric value with no decimal component. The floorMethodCallExpr syntax rule defines how the floor function is invoked.

Example 88: all orders with freight costs that round down to 32

http://host/service/Orders?$filter=floor(Freight) eq 32

5.1.1.9.3 round

The round function has the following signatures

Edm.Double round(Edm.Double)
Edm.Decimal round(Edm.Decimal)

The round function rounds the input numeric parameter to the nearest numeric value with no decimal component. The mid-point between two integers is rounded away from zero, i.e. 0.5 is rounded to 1 and ‑0.5 is rounded to -1. The roundMethodCallExpr syntax rule defines how the round function is invoked.

Example 89: all orders with freight costs that round to 32

http://host/service/Orders?$filter=round(Freight) eq 32

5.1.1.10 Type Functions

5.1.1.10.1 cast

The cast function has the following signatures:

type cast(type)
type cast(expression,type)

The single parameter cast function returns the current instance cast to the type specified. The two-parameter cast function returns the object referred to by the expression cast to the type specified.

The cast function follows these assignment rules:

·       The null value can be cast to any type.

·       Primitive types are cast to Edm.String or a type definition based on it by using the literal representation used in payloads, and WKT (well-known text) format for Geo types, see rules fullCollectionLiteral, fullLineStringLiteral, fullMultiPointLiteral, fullMultiLineStringLiteral, fullMultiPolygonLiteral, fullPointLiteral, and fullPolygonLiteral in [OData-ABNF]. The cast fails if the target type specifies an insufficient MaxLength.

·       Edm.String, or a type definition based on Edm.String, can be cast to a primitive type if the string contains a literal representation for the target type.

·       Numeric primitive types are cast to each other with appropriate rounding. The cast fails if the integer part doesn't fit into target type.

·       Edm.DateTimeOffset, Edm.Duration, and Edm.TimeOfDay values can be cast to the same type with a different precision with appropriate rounding.

·       Non-Unicode string values can be cast to a Unicode string type definition. Unicode string values can be cast to non-Unicode string type definition if the Unicode string only contains ASCII characters.

·       Structured types are assignable to their type or a direct or indirect base type.

·       Collections are cast item by item.

The cast function is optional for primitive values (first five rules) and up-casts (seventh rule).

If the cast fails, the cast function returns null.

5.1.1.10.2 isof

The isof function has the following signatures

Edm.Boolean isof(type)
Edm.Boolean isof(expression,type)

The single parameter isof function returns true if the current instance is assignable to the type specified, according to the assignment rules for the cast function, otherwise it returns false.

The two parameter isof function returns true if the object referred to by the expression is assignable to the type specified, according to the same rules, otherwise it returns false.

The isofExpr syntax rule defines how the isof function is invoked.

Example 90: orders that are also BigOrders

http://host/service/Orders?$filter=isof(NorthwindModel.BigOrder)

http://host/service/Orders?$filter=isof($it,NorthwindModel.BigOrder)

Example 91: orders of a customer that is a VIPCustomer

http://host/service/Orders?$filter=isof(Customer,NorthwindModel.VIPCustomer)

5.1.1.11 Geo Functions

5.1.1.11.1 geo.distance

The geo.distance function has the following signatures:

Edm.Double geo.distance(Edm.GeographyPoint,Edm.GeographyPoint)
Edm.Double geo.distance(Edm.GeometryPoint,Edm.GeometryPoint)

The geo.distance function returns the shortest distance between the two points in the coordinate reference system signified by the two points’ SRIDs.

5.1.1.11.2 geo.intersects

The geo.intersects function has the following signatures:

Edm.Boolean geo.intersects(Edm.GeographyPoint,Edm.GeographyPolygon)
Edm.Boolean geo.intersects(Edm.GeometryPoint,Edm.GeometryPolygon)

The geo.intersects function returns true if the specified point lies within the interior or on the boundary of the specified polygon, otherwise it returns false.

5.1.1.11.3 geo.length

The geo.length function has the following signatures:

Edm.Double geo.length(Edm.GeographyLineString)
Edm.Double geo.length(Edm.GeometryLineString)

The geo.length function returns the total length of its line string parameter in the coordinate reference system signified by its SRID.

5.1.1.12 Lambda Operators

OData defines two operators that evaluate a Boolean expression on a collection. Both must be prepended with a navigation path that identifies a collection.

4.01 Services MUST support case-insensitive lambda operator names. Clients that want to work with 4.0 services MUST use lower case lambda operator names.

The argument of a lambda operator is a case-sensitive lambda variable name followed by a colon (:) and a Boolean expression that uses the lambda variable name to refer to properties of members of the collection identified by the resource path.

If the name chosen for the lambda variable matches a property name of the current resource referenced by the resource path, the lambda variable takes precedence. Clients can prefix properties of the current resource referenced by the resource path with $it.

5.1.1.12.1 any

The any operator applies a Boolean expression to each member of a collection and returns true if and only if the expression is true for any member of the collection, otherwise it returns false. This implies that the any operator always returns false for an empty collection.

The any operator can be used without an argument expression. This short form returns false if and only if the collection is empty.

Example 92: all Orders that have any Items with a Quantity greater than 100

http://host/service/Orders?$filter=Items/any(d:d/Quantity gt 100)

5.1.1.12.2 all

The all operator applies a Boolean expression to each member of a collection and returns true if the expression is true for all members of the collection, otherwise it returns false. This implies that the all operator always returns true for an empty collection.

The all operator cannot be used without an argument expression.

Example 93: all Orders that have only Items with a Quantity greater than 100

http://host/service/Orders?$filter=Items/all(d:d/Quantity gt 100)

5.1.1.13 Literals

5.1.1.13.1 Primitive Literals

Primitive literals can appear in the resource path as key property values, and in the query part, for example, as operands in $filter expressions. They are represented according to the primitiveLiteral rule in [OData-ABNF].

Example 94: expressions using primitive literals

NullValue eq null

TrueValue eq true

FalseValue eq false

Custom.Base64UrlDecode(binary'T0RhdGE') eq 'OData'

IntegerValue lt -128

DoubleValue ge 0.31415926535897931e1

SingleValue eq INF

DecimalValue eq 34.95

StringValue eq 'Say Hello,then go'

DateValue eq 2012-12-03

DateTimeOffsetValue eq 2012-12-03T07:16:23Z

DurationValue eq duration'P12DT23H59M59.999999999999S'

DurationValue eq 'P12DT23H59M59.999999999999S'

TimeOfDayValue eq 07:59:59.999

GuidValue eq 01234567-89ab-cdef-0123-456789abcdef

Int64Value eq 0

ColorEnumValue eq Sales.Pattern'Yellow',

ColorEnumValue eq 'Yellow',

geo.distance(Location,geography'SRID=0;Point(142.1 64.1)')

Duration literals in OData 4.0 required prefixing with “duration”. Enumeration literals in OData 4.0 required prefixing with the qualified type name of the enumeration.

In OData 4.01, services MUST support duration and enumeration literals with or without the type prefix. OData clients that want to operate across OData 4.0 and OData 4.01 services should always include the prefix for duration and enumeration types.

5.1.1.13.2 Complex and Collection Literals

Complex literals and collection literals in URLs are represented as JSON objects and arrays according to the arrayOrObject rule in [OData-ABNF]. Such literals MUST NOT appear in the path portion of the URL but can be passed to bound functions and function imports in path segments by using parameter aliases.

Note that the special characters {, }, [, ], and " MUST be percent-encoded in URLs although some browsers will accept and pass them on unencoded.

Example 95: collection of string literals

http://host/service/ProductsByColors(colors=@c)?@c=["red","green"]

5.1.1.13.3 null

The null literal can be used to compare a value to null, or to pass a null value to a function.

5.1.1.13.4 $it

The $it literal can be used in expressions to refer to the current instance of the resource identified by the resource path. For a collection-valued resource the current instance is the instance currently being evaluated by the system query option. For a single-valued resource it is the resource itself.

It allows comparing properties of related entities to properties of the current instance in expressions within lambda operators or in $filter expressions nested within $expand or $select.

It also can be used in $filter and $orderby expressions on collections of primitive types to refer to the current primitive instance, but using the $this literal is preferred as $this can also be used in $filter and $orderby expressions nested within $select.

Note: property names and property paths in $filter expressions nested within $expand are evaluated in the context of the declared type of the expanded navigation property, so property names and property paths for the current instance of the collection identified by the resource path MUST be prefixed with $it/.

The $it literal can also be used as a path prefix to invoke a bound function overload on the current instance within an expression. Function names without a path prefix refer to an unbound function overload.

Example 96: email addresses ending with .com assuming EmailAddresses is a collection of strings

http://host/service/Customers(1)/EmailAddresses?$filter=endswith($it,'.com')

Example 97: customers along with their orders that shipped to the same city as the customer's address. The nested filter expression is evaluated in the context of Orders; $it allows referring to values in the outer context of Customers.

http://host/service/Customers?
            $expand=Orders($filter=$it/Address/City eq ShipTo/City)

Example 98: products with at least 10 positive reviews. Model.PositiveReviews is a function bound to Model.Product returning a collection of reviews.

http://host/service/Products?$filter=$it/Model.PositiveReviews()/$count ge 10

5.1.1.13.5 $root

The $root literal can be used in expressions to refer to resources of the same service. It can be used as a single-valued expression or within complex or collection literals.

Example 99: all employees with the same last name as employee A1235

http://host/service/Employees?
                         $filter=LastName eq $root/Employees('A1245')/LastName

Example 100: products ordered by a set of customers, where the set of customers is passed as a JSON array containing the resource paths from $root to each customer.

http://host/service/ProductsOrderedBy(Customers=@c)?
                        @c=[$root/Customers('ALFKI'),$root/Customers('BLAUS')]

5.1.1.13.6 $this

The $this literal can be used in $filter and $orderby expressions nested within $expand and $select for collection-valued properties and navigation properties. It refers to the current instance of the collection.

Example 101: select only email addresses ending with .com

http://host/service/Customers?
    $select=EmailAddresses($filter=endswith($this,'.com'))

5.1.1.14 Path Expressions

Properties and navigation properties of the entity type of the set of resources that are addressed by the request URL can be used as operands or function parameters, as shown in the preceding examples.

Properties of complex properties can be used via the same syntax as in resource paths, i.e. by specifying the name of a complex property, followed by a forward slash (/) and the name of a property of the complex property, and so on,

Properties and navigation properties of entities related with a target cardinality 0..1 or 1 can be used by specifying the navigation property, followed by a forward slash (/) and the name of a property of the related entity, and so on.

If a complex property is null, or no entity is related (in case of target cardinality 0..1), its value, and the values of its components, are treated as null.

Example 102: similar behavior whether HeadquarterAddress is a nullable complex type or a nullable navigation property

Companies(1)/HeadquarterAddress/Street

To access properties of derived types, the property name MUST be prefixed with the qualified name of the derived type on which the property is defined, followed by a forward slash (/), see addressing derived types. If the current instance is not of the specified derived type, the path expression returns null.

If the property or navigation property is not defined for the type of the resource and that type supports dynamic properties or navigation properties, then the property or navigation property is treated as null for all instances on which it has no value.

If the property or navigation property is not defined for the type of the resource and that type does not support dynamic properties or navigation properties, then the request may be considered malformed.

5.1.1.15 Annotation Values in Expressions

Services MAY support the use of annotation values as operands or function parameters.

Annotation values are referenced by the annotation name which consists of an at sign (@) followed by the qualified term name, optionally followed by a hash (#) and an annotation qualifier. The annotation name can be prefixed with a path expression (see section 5.1.1.13.6) leading to the annotated resource or property.

If an annotation is not applied to the resource or property, then its value, and the values of its components, are treated as null.

Example 103: Return Products that have prices in Euro

http://host/service/Products?

    $filter=Price/@Measures.Currency eq 'EUR'

Example 90: Return Employees that have any error messages in the Core.Message annotation

http://host/service/Employees?

    $filter=@Core.Messages/any(m:m/severity eq 'error')

Services MAY additionally support the use of the unqualified term name by defining one or more default namespaces through the Core.DefaultNamespace annotation term defined in [OData-VocCore]. For more information on default namespaces, see Default Namespaces in [OData-Protocol]. This short notation however uses the same name pattern as parameter aliases. If a query option is specified as a parameter alias, then any occurrence of the parameter alias name in an expression MUST evaluate to the parameter alias value and MUST NOT evaluate to the annotation value of an identical unqualified term name.

5.1.1.16 Operator Precedence

OData services MUST use the following operator precedence for supported operators when evaluating $filter and $orderby expressions. Operators are listed by category in order of precedence from highest to lowest. Operators in the same category have equal precedence:

Group

Operator

Description

ABNF Expression

Grouping

( )

Precedence grouping

parenExpr

boolParenExpr

Primary

/

Navigation

firstMemberExpr

memberExpr

 

has

Enumeration Flags

hasExpr

 

in

Is a member of

inExpr

 

xxx( )

Method Call

methodCallExpr

boolMethodCallExpr

functionExpr

Unary

-

Negation

negateExpr

 

not

Logical Negation

notExpr

 

cast( )

Type Casting

castExpr

Multiplicative

mul

Multiplication

mulExpr

 

div

Division

divExpr

 

divby

Decimal Division

divbyExpr

 

mod

Modulo

modExpr

Additive

add

Addition

addExpr

 

sub

Subtraction

subExpr

Relational

gt

Greater Than

gtExpr

 

ge

Greater than or Equal

geExpr

 

lt

Less Than

ltExpr

 

le

Less than or Equal

leExpr

 

isof

Type Testing

isofExpr

Equality

eq

Equal

eqExpr

 

ne

Not Equal

neExpr

Conditional AND

and

Logical And

andExpr

Conditional OR

or

Logical Or

orExpr

5.1.1.17 Numeric Promotion

Services SHOULD NOT require explicit cast operations between numeric types used in comparison expressions. Wherever possible, such comparisons should be performed using underlying types of sufficient size.

Services MAY support numeric promotion for arithmetic operations or when comparing two operands of comparable types by applying the following rules, in order:

·       If either operand is Edm.Double, the other operand is converted to type Edm.Double.

·       Otherwise, if either operand is Edm.Single, the other operand is converted to type Edm.Single.

·       Otherwise, if either operand is of type Edm.Decimal, the other operand is converted to Edm.Decimal.

·       Otherwise, if either operand is Edm.Int64, the other operand is converted to type Edm.Int64.

·       Otherwise, if either operand is Edm.Int32, the other operand is converted to type Edm.Int32.

·       Otherwise, if either operand is Edm.Int16, the other operand is converted to type Edm.Int16.

Each of these promotions uses the same semantics as a castExpression to promote an operand to the target type.

OData does not define an implicit conversion between string and numeric types.

5.1.2 System Query Option $expand

The $expand system query option specifies the related resources or media streams to be included in line with retrieved resources.

What follows is a (non-normative) snippet from [OData-ABNF] that describes the syntax of $expand:

expand            = '$expand' EQ expandItem *( COMMA expandItem )

expandItem        = STAR [ ref / OPEN levels CLOSE ]
                  / "$value"
                  / expandPath
                    [ ref   [ OPEN expandRefOption  
                           *( SEMI expandRefOption   ) CLOSE ]
                    / count [ OPEN expandCountOption
                           *( SEMI expandCountOption ) CLOSE ]
                    /         OPEN expandOption
                           *( SEMI expandOption      ) CLOSE
                    ]

expandPath        = [ ( qualifiedEntityTypeName
                      / qualifiedComplexTypeName
                      ) "/" ]
                    *( ( complexProperty / complexColProperty ) "/"
                       [ qualifiedComplexTypeName "/" ] )
                    ( STAR
                    / streamProperty
                    / navigationProperty [ "/" qualifiedEntityTypeName ]
                    )

expandCountOption = filter
                  / search

expandRefOption   = expandCountOption
                  / orderby
                  / skip
                  / top
                  / inlinecount

expandOption      = expandRefOption
                  / select
                  / expand
                  / compute
                  / levels
                  / aliasAndValue

Each expandItem is evaluated relative to the entity containing the navigation or stream property being expanded.

A type cast using the qualifiedEntityTypeName to a type containing the property is required in order to expand a navigation or stream property defined on a derived type.

An arbitrary number of single- or collection-valued complex properties, optionally followed by a type cast, allow drilling into complex properties.

If the type does not support dynamic properties, then the navigationProperty or streamProperty segment MUST identify a navigation or stream property defined on the entity type of the request, the derived entity type specified in the type cast, or the last complex type identified by the complex property path. Otherwise, if the type does support dynamic navigation properties and the navigationProperty or streamProperty segment does not identify a declared navigation or stream property, then the expanded property appears only for those instances on which it has a value.

Example 104: expand a navigation property of an entity type

http://host/service/Products?$expand=Category

Example 105: expand a navigation property of a complex type

http://host/service/Customers?$expand=Addresses/Country

A property MUST NOT appear in more than one expandItem.

Query options can be applied to an expanded navigation property by appending a semicolon-separated list of query options, enclosed in parentheses, to the navigation property name. Allowed system query options are $filter, $select, $orderby, $skip, $top, $count, $search, and $expand.

Example 106: all categories and for each category all related products with a discontinued date equal to null

http://host/service/Categories?

                             $expand=Products($filter=DiscontinuedDate eq null)

The $count segment can be appended to a navigation property name or type-cast segment following a navigation property name to return just the count of the related entities. The $filter and $search system query options can be used to limit the number or related entities included in the count.

Example 107: all categories and for each category the number of all related products

http://host/service/Categories?$expand=Products/$count

Example 108: all categories and for each category the number of all related blue products

http://host/service/Categories?$expand=Products/$count($search=blue)

To retrieve entity references instead of the related entities, append /$ref to the navigation property name or type-cast segment following a navigation property name.

Example 109: all categories and for each category the references of all related products

http://host/service/Categories?$expand=Products/$ref

Example 110: all categories and for each category the references of all related products of the derived type Sales.PremierProduct

http://host/service/Categories?$expand=Products/Sales.PremierProduct/$ref

Example 111: all categories and for each category the references of all related premier products with a current promotion equal to null

http://host/service/Categories?
   $expand=Products/Sales.PremierProduct/$ref($filter=CurrentPromotion eq null)

Cyclic navigation properties (whose target type is identical or can be cast to its source type) can be recursively expanded using the special $levels option. The value of the $levels option is either a positive integer to specify the number of levels to expand, or the literal string max to specify the maximum expansion level supported by that service. A $levels option with a value of 1 specifies a single expand with no recursion.

Example 112: all employees with their manager, manager's manager, and manager's manager's manager

http://host/service/Employees?$expand=ReportsTo($levels=3)

It is also possible to expand all declared and dynamic navigation properties using a star (*). To retrieve references to all related entities use */$ref, and to expand all related entities with a certain distance use the star operator with the $levels option. The star operator can be combined with explicitly named navigation properties, which take precedence over the star operator.

The star operator does not implicitly include stream properties.

Example 113: expand Supplier and include references for all other related entities

http://host/service/Categories?$expand=*/$ref,Supplier

Example 114: expand all related entities and their related entities

http://host/service/Categories?$expand=*($levels=2)

Specifying a stream property includes the media stream inline according to the specified format.

Example 115: include Employee’s Photo stream property along with other properties of the customer

http://host/service/Employees?$expand=Photo

Specifying $value for a media entity includes the media entity’s stream value inline according to the specified format.

Example 116: Include the Product’s media stream along with other properties of the product

http://host/service/Products?$expand=$value

5.1.3 System Query Option $select

The $select system query option allows clients to request a specific set of properties for each entity or complex type.

The $select query option is often used in conjunction with the $expand system query option, to define the extent of the resource graph to return ($expand) and then specify a subset of properties for each resource in the graph ($select). Expanded navigation properties MUST be returned, even if they are not specified as a selectItem.

What follows is a (non-normative) snippet from [OData-ABNF] showing the syntax of $select:

select         = '$select' EQ selectItem *( COMMA selectItem )

selectItem     = STAR               
               / allOperationsInSchema
               / [ ( qualifiedEntityTypeName
                   / qualifiedComplexTypeName
                   ) "/"
                 ]
                 ( selectProperty
                 / qualifiedActionName 
                 / qualifiedFunctionName 
                 )

selectProperty = primitiveProperty 
               / primitiveColProperty
                 [ OPEN selectOptionPC *( SEMI selectOptionPC ) CLOSE ]
               / navigationProperty
               / selectPath
                 [ OPEN selectOption *( SEMI selectOption ) CLOSE
                 / "/" selectProperty
                 ]

selectPath     = ( complexProperty / complexColProperty )
                 [ "/" qualifiedComplexTypeName ]

selectOptionPC = filter / search / inlinecount / orderby / skip / top

selectOption   = selectOptionPC
   
               / compute / select / expand / aliasAndValue   

The $select system query option is interpreted relative to the entity type or complex type of the resources identified by the resource path section of the URL. Each selectItem in the $select clause indicates that the response MUST include the declared or dynamic properties, actions and functions identified by that selectItem. The simplest form of a selectItem explicitly requests a property defined on the entity type of the resources identified by the resource path section of the URL.

Example 117: rating and release date of all products

http://host/service/Products?$select=Rating,ReleaseDate

It is also possible to request all declared and dynamic structural properties using a star (*).

Example 118: all structural properties of all products

http://host/service/Products?$select=*

If the selectItem is not defined for the type of the resource, and that type supports dynamic properties, then the property is treated as null for all instances on which it is not defined.

If the selectItem is not defined for the type of the resource, and that type does not support dynamic properties, then the request is considered malformed.

If the selectItem is a navigation property then the corresponding navigation link is represented in the response. If the navigation property also appears in an $expand query option then it is additionally represented as inline content. This inline content can itself be restricted with a nested $select query option, see section 5.1.2.

Example 119: name and description of all products, plus name of expanded category

http://host/service/Products?
                       $select=Name,Description&$expand=Category($select=Name)

The selectItem MUST be prefixed with a qualifiedEntityTypeName or qualifiedComplexTypeName in order to select a property defined on a type derived from the type of the resource segment.

A selectItem that is a complex type or collection of complex type can be followed by a forward slash, an optional type-cast segment, and the name of a property of the complex type (and so on for nested complex types).

Example 120: the AccountRepresentative property of any supplier that is of the derived type Namespace.PreferredSupplier, together with the Street property of the complex property Address, and the Location property of the derived complex type Namespace.AddressWithLocation

http://host/service/Suppliers?
     $select=Namespace.PreferredSupplier/AccountRepresentative,
             Address/Street,
             Address/Namespace.AddressWithLocation/Location

Query options can be applied to a selectItem that is a path to a single complex value or a collection of primitive or complex values by appending a semicolon-separated list of query options, enclosed in parentheses, to the selectItem. The allowed system query options depend on the type of the resource identified by the selectItem, see section System Query Options . A property MUST NOT have select options specified in more than one place in a request and MUST NOT have both select options and expand options specified.

Example 121: select up to five  addresses whose City starts with an H, sorted, and with the Country expanded

http://host/service/Customers?$select=Addresses($filter=startswith(City,'H');$top=5;$orderby=Country/Name,City,Street;$expand=Country)

Any structural property, non-expanded navigation property, or operation not requested as a selectItem (explicitly or via a star) SHOULD be omitted from the response.

If any selectItem (including a star) is specified, actions and functions SHOULD be omitted unless explicitly requested using a qualifiedActionName, a qualifiedFunctionName or the allOperationsInSchema.

If an action or function is requested as a selectItem, either explicitly by using a qualifiedActionName or qualifiedFunctionName clause, or implicitly by using allOperationsInSchema, then the service includes information about how to invoke that operation for each entity identified by the last path segment in the request URL for which the operation can be bound.

If an action or function is requested in a selectItem using a qualifiedActionName or a qualifiedFunctionName and that operation cannot be bound to the entities requested, the service MUST ignore the selectItem.

Example 122: the ID property, the ActionName action defined in Model and all actions and functions defined in the Model2 for each product if those actions and functions can be bound to that product

http://host/service/Products?$select=ID,Model.ActionName,Model2.*

When multiple selectItems exist in a select clause, then the total set of properties, open properties, navigation properties, actions and functions to be returned is equal to the union of the set of those identified by each selectItem.

If a selectItem is a path expression requesting a component of a complex property and the complex property is null on an instance, then the component is treated as null as well.

5.1.4 System Query Option $orderby

The $orderby system query option allows clients to request resources in a particular order.

The semantics of $orderby are covered in the [OData-Protocol] document.

The [OData-ABNF] orderby syntax rule defines the formal grammar of the $orderby query option.

5.1.5 System Query Options $top and $skip

The $top system query option requests the number of items in the queried collection to be included in the result. The $skip query option requests the number of items in the queried collection that are to be skipped and not included in the result. A client can request a particular page of items by combining $top and $skip.

The semantics of $top and $skip are covered in the [OData-Protocol] document. The [OData-ABNF] top and skip syntax rules define the formal grammar of the $top and $skip query options respectively.

5.1.6 System Query Option $count

The $count system query option allows clients to request a count of the matching resources included with the resources in the response. The $count query option has a Boolean value of true or false.

The semantics of $count is covered in the [OData-Protocol] document.

5.1.7 System Query Option $search

The $search system query option allows clients to request items within a collection matching a free-text search expression.

The $search query option can be applied to a URL representing a collection of entity, complex, or primitive typed instances, to return all matching items within the collection. Applying the $search query option to the $all resource requests all matching entities in the service.

If both $search and $filter are applied to the same request, the results include only those items that match both criteria.

The [OData-ABNF] search syntax rule defines the formal grammar of the $search query option.

Example 123: all products that are blue or green. It is up to the service to decide what makes a product blue or green.

http://host/service/Products?$search=blue OR green

5.1.7.1 Search Expressions

Search expressions are used within the $search system query option to request entities matching the specified expression.

Terms can be any single word to be matched within the expression.

Terms enclosed in double-quotes comprise a phrase.

Each individual term or phrase comprises a Boolean expression that returns true if the term or phrase is matched, otherwise false. The semantics of what is considered a match is dependent upon the service.

Expressions enclosed in parenthesis comprise a group expression.

The search expression can contain any number of terms, phrases, or group expressions, along with the case-sensitive keywords NOT, AND, and OR, evaluated in that order.

Expressions prefaced with NOT evaluate to true if the expression is not matched, otherwise false.

Two expressions not enclosed in quotes and separated by a space are equivalent to the same two expressions separated by the AND keyword. Such expressions evaluate to true if both of the expressions evaluate to true, otherwise false.

Expressions separated by an OR evaluate to true if either of the expressions evaluate to true, otherwise false.

The [OData-ABNF] searchExpr syntax rule defines the formal grammar of the search expression.

5.1.8 System Query Option $format

The $format system query option allows clients to request a response in a particular format and is useful for clients without access to request headers for standard content-type negotiation. Where present $format takes precedence over standard content-type negotiation.

The semantics of $format is covered in the [OData-Protocol] document.

The [OData-ABNF] format syntax rule defines the formal grammar of the $format query option.

5.1.9 System Query Option $compute

The $compute system query option allows clients to define computed properties that can be used in a $select or within a $filter or $orderby expression.

Following is a (non-normative) snippet from [OData-ABNF] showing the syntax of $compute:

compute          = '$compute' EQ computeItem *( COMMA computeItem )

computeItem      = commonExpr RWS 'as' RWS computedProperty

computedProperty = odataIdentifier  

The $compute system query option is interpreted relative to the entity type or complex type of the resources identified by the resource path section of the URL.

Computed properties SHOULD be included as dynamic properties in the result and MUST be included if $select is specified with the computed property name, or star (*).

Example 124: compute total price for order items

http://host/service/Orders(10)/Items?$select=Product/Description,Total
       &$filter=Total gt 100&$orderby=Total
       &$compute=Product/Price mul Quantity as Total

5.1.10 System Query Option $index

The $index system query option allows clients to do a positional insert into a collection annotated with using the Core.PositionalInsert term (see [OData-VocCore]). The value of the $index system query option is the zero-based ordinal position where the item is to be inserted. The ordinal of items within the collection greater than or equal to the inserted position are increased by one. A negative ordinal indexes from the end of the collection, with -1 representing an insert at the end of the collection.

The [OData-ABNF] index syntax rule defines the formal grammar of the $index query option.

5.1.11 System Query Option $schemaversion

The $schemaversion system query option allows clients to specify the version of the schema against which the request is made. The semantics of $schemaversion is covered in the [OData-Protocol] document.

The [OData-ABNF] schemaversion syntax rule defines the formal grammar of the $schemaversion query option

5.2 Custom Query Options

Custom query options provide an extensible mechanism for service-specific information to be placed in a URL query string. A custom query option is any query option of the form shown by the rule customQueryOption in [OData-ABNF].

Custom query options MUST NOT begin with a $ or @ character.

Example 125: service-specific custom query option debug-mode

http://host/service/Products?debug-mode=true

5.3 Parameter Aliases

Parameter aliases can be used in place of literal values in entity keys, function parameters, or within a $filter or $orderby expression.

Parameter aliases MUST start with an @ character, see rule parameterAlias in [OData-ABNF].

The semantics of parameter aliases are covered in [OData-Protocol]. The [OData-ABNF] rule aliasAndValue defines the formal grammar for passing parameter alias values as query options.

Example 126:

http://host/service/Movies?$filter=contains(@word,Title)&@word='Black'

Example 127:

http://host/service/Movies?$filter=Title eq @title&@title='Wizard of Oz'

Example 128: JSON array of strings as parameter alias value – note that [, ], and " need to be percent-encoded in real URLs, the clear-text representation used here is just for readability

http://host/service/Products/Model.WithIngredients(Ingredients=@i)?@i=["Carrots","Ginger","Oranges"]

6     Conformance

The conformance requirements for OData clients and services are described in [OData-Protocol].

Appendix A.  Acknowledgments

The contributions of the OASIS OData Technical Committee members, enumerated in [OData-Protocol], are gratefully acknowledged.

Appendix B.  Revision History

Revision

Date

Editor

Changes Made

Working Draft 01

2016-06-22

Michael Pizzo

Ralf Handl

Transferred content from OData 4.0 Part 2 – URL Conventions Errata 3

Committee Specification Draft 01

2016-12-08

Michael Pizzo

Ralf Handl

Integrated 4.01 features

·         Alternate keys

·         Key-as-segment convention

·         Operators in and divby

·         $expand with stream properties

·         $compute system query option

·         $index system query option

Committee Specification Draft 02

2017-06-08

Michael Pizzo

Ralf Handl

More 4.01 features

·         Set-based operations

·         $expand, $select, $filter with POST and PATCH

·         Instance annotations in query options

·         $schemaversion system query option

Committee Specification Draft 03

2017-09-28

Michael Pizzo

Ralf Handl

Incorporated review feedback

Added nested query options within $select

Added nested alias value assignments within $expand and $select