Is Max String Length Metadata possible from WCF Data Services (OData)?

1
votes

I am using WCF Data Services (OData) to expose some data that is a varchar(10) in my SQL Server Database. (I am using entity framework to expose it.)

Is there a way to ask the OData endpoint how long a string can be (ie get the 10 from varchar(10))?

1
wcf-data-servicesodata

1 Answers

1
votes

If the service is an EF based service, and your CSDL for the EF model contains the max string length attribute on the property, then the $metadata of the service will contain that attribute as well. The client can then parse the $metadata and ask for this. Note that the WCF DS Client library doesn't have an API to do this though. You could use ODataLib and EdmLib to read the $metadata (or just plain XML). They are in Microsoft.Data.OData.dll and Microsoft.Data.Edm.dll in the latest CTP (http://blogs.msdn.com/b/astoriateam/archive/2011/10/13/announcing-wcf-data-services-oct-2011-ctp-for-net-4-and-silverlight-4.aspx). Note though, that if the service is based on something else than EF, then it's currently not possible to customize the $metadata endpoint in WCF DS itself this way. You would have to expose the $metadata yourself in some other way.