[ODATA-165] Support Cross-joins - OASIS Technical Committees Issue Tracker

Details

Type: New Feature
Status: Closed
Priority: Major
Resolution: Fixed
Affects Version/s: V4.0_WD01
Fix Version/s: V4.0_CSD02
Component/s: ABNF, URL Conventions
Labels:
None
Environment:

[Applied]

Proposal:

Hide

Advanced clients MAY request cross-joins, i.e. posing queries (based on other join conditions, with $expand for the entity sets to be joined, and add $filter to specify the equivalent of the join condition) in the case where the spanning entity sets are not all related by an association .
To enable this potentially useful capability, the server SHOULD allow requests to be rooted at the entity container, and in doing so the latter MUST either provide explicit navigation properties in the model (i.e. where useful navigations exist) or MUST define implicit navigation properties with cardinality "to one" to each entity set (and potentially each function) it contains, so that queries across entity sets could be supported by referring to properties qualified by entity set.
In any of the two cases, the entity container SHOULD be annotated in the same way as entity sets to express which aggregate queries are supported.

(For an example please see inside comments.)

Accepted: https://www.oasis-open.org/committees/download.php/48622/odata-meeting-30_on-20130321-minutes.html#odata-165

Show
Advanced clients MAY request cross-joins, i.e. posing queries (based on other join conditions, with $expand for the entity sets to be joined, and add $filter to specify the equivalent of the join condition) in the case where the spanning entity sets are not all related by an association . To enable this potentially useful capability, the server SHOULD allow requests to be rooted at the entity container, and in doing so the latter MUST either provide explicit navigation properties in the model (i.e. where useful navigations exist) or MUST define implicit navigation properties with cardinality "to one" to each entity set (and potentially each function) it contains, so that queries across entity sets could be supported by referring to properties qualified by entity set. In any of the two cases, the entity container SHOULD be annotated in the same way as entity sets to express which aggregate queries are supported. (For an example please see inside comments.) Accepted: https://www.oasis-open.org/committees/download.php/48622/odata-meeting-30_on-20130321-minutes.html#odata-165
Resolution:

Hide

https://www.oasis-open.org/committees/download.php/48584/odata-core-v4.0-wd01-part1-protocol-2013-03-19.doc
https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/vocabularies/Org.OData.Core.V1.xml?rev=295

https://www.oasis-open.org/committees/download.php/49202/odata-v4.0-wd02-part2-url-conventions-2013-05-16.docx

Accepted: https://www.oasis-open.org/committees/download.php/49557/odata-meeting-41_on-20130613_14-F2F-minutes.html#odata-165

https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/ABNF/odata-abnf-construction-rules.txt?rev=215
https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/ABNF/odata-abnf-testcases.xml?rev=215

Show
https://www.oasis-open.org/committees/download.php/48584/odata-core-v4.0-wd01-part1-protocol-2013-03-19.doc https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/vocabularies/Org.OData.Core.V1.xml?rev=295 https://www.oasis-open.org/committees/download.php/49202/odata-v4.0-wd02-part2-url-conventions-2013-05-16.docx Accepted: https://www.oasis-open.org/committees/download.php/49557/odata-meeting-41_on-20130613_14-F2F-minutes.html#odata-165 https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/ABNF/odata-abnf-construction-rules.txt?rev=215 https://tools.oasis-open.org/version-control/browse/wsvn/odata/trunk/spec/ABNF/odata-abnf-testcases.xml?rev=215

Description

We often have requests to support queries that span entitysets. Where navigation properties exist between the entitysets these provide a natural and convenient mechanism for building queries that span entitysets. However, where navigation properties are not present a way is needed to build such cross-entity spanning queries.

In the context of looking at aggregation we came up with a solution for doing this by considering the entitycontainer as the cross-product of the contained entitysets. You could then $expand the entitysets you wanted to join, and add a filter to specify the equivalent of the join condition. This seemed generally useful beyond just the scope of aggregation.

Support Cross-joins

Details

Description

Attachments

Activity

People

Dates