Xcode is an IDE. The question as posed doesn't make any sense.
I think what you're asking is does Xcode provide the same hooks (headers, libraries, etc.) that, say Visual Studio does, when writing an application that reads/writes data to a MS SQL Server database. The answer depends in a very big way on what language/API you're using to do this. Raw SQL? Embedded SQL? PHP? Perl DBI? Java?