Accessing SQL Data Services (SDS) using ADO.NET Data Services (Astoria)

sxk — Fri, 31 Oct 2008 15:08:46 GMT

With the latest release of the SQL Data Services (SDS) we announced a tech preview of the work we did with ADO.NET Data Services (Astoria/adods) team (http://www.microsoft.com/azure/sqllabs.mspx). As part of this preview we made available a new SDS service head that supports a subset of conventions outlined by ADO.NET Data Services. A number of people stopped at our PDC demo booth and ask for details. Here are some of the answers. Keep in mind that this is just a tech preview and can change in future service updates.

Scope

This preview version of adods service head supports GET, POST, PUT and DELETE requests within a container. This means that you can use ADO.NET Data Services conventions to create, modify, query and delete entities within a container. However, you cannot perform any operations on authorities or containers. At this point we also don’t support cross-container operations.

Accessing adods service head

Accessing adods service head is very similar to accessing our existing soap head – all you need to do is add /adods/v1/ to the service URI:

https://<authorityID>.data.database.windows.net/adods/v1/

Since all requests have to be targeted at a single container, you will also have to specify the name of the container in the URL:

https://<authorityID>.data.database.windows.net/adods/v1/<containerID/

Any request that doesn’t specify a container will result in HTTP 501 Not Implemented error.

Querying SDS using ADO.NET Data Services conventions

· Let’s start with a few simple queries. The following query returns all entities within a container: https://<authorityID>.data.database.windows.net/adods/v1/<containerID>/Entities()

· To retrieve a specific entity, you can specify its ID: https://<authorityID>.data.database.windows.net/adods/v1/<containerID>/Entities('entityID')

· You can use $filter to filter the set returned to you: https://<authorityID>.data.database.windows.net/adods/v1/<containerID>/Entities()?$filter=Kind eq 'Books'

· You can also order the set by using $orderby: https://<authorityID>.data.database.windows.net/adods/v1/<containerID>/Entities()?$filter=Kind eq 'Books'&$orderby=Title You can also specify multiple orderby parameters as well as ascending or descending order. If $orderby is not specified, the entities are ordered by Id. Note: $orderby option will not result in filtering of the entities set returned by the filter. This means that a query with an $orderby clause will return the same number of entities as the same query without the $orderby. It also means that all entities, including the ones which do not have the $orderby proprety, will be returned.

· Finally, you can limit the number of results returned using $top: https://<authorityID>.data.database.windows.net/adods/v1/<containerID>/Entities()?$filter=Kind eq 'Books'&$orderby=Title&$top=10 As with REST and SOAP heads, SDS will return a maximum of 500 entities at a time.

System properties

All SDS entities have three system properties: Id, Kind and Version. While it is possible to create and access flexible properties with the same names using REST or SOAP heads, it isn’t possible with adods head. If “Kind”, “Id” or “Version” appear in the $filter or $orderby clauses, SDS will filter/order on the system properties.