Hi Paul,
SQL 2012 has a new dll Client driver dll called SQLNCLI11.dll. We had to add this to our Driver list when SQL 2008 came out so CR would recognize the client dll. MS doesn't support MDAC to SQL 2008 and likely not SQL 2012 either, or it's limited support only by MS.
As for supporting SQL Express 2012 if you can't select a PC name, User, PW and database in our UI then I doubt this is going to work.
I have the SQL 2012 client installed, so when I create a report in the .NET IDE and use the database wizard I see these drivers:
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but then to actually connect I MUST fill in the next screen with valid info:
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Clik here to view.
If you can't then CR won't support it, if SQL 2012 doesn't support an interface then how would you fill the info in manually just to test?
Possibly a UDL might work. Open Notepad and create an empty text file and save it to your Desktop. Rename the file to *.UDL. Now double click the file and it should bring up MS OLE DB Log on dialog box and you cna select the 11 driver but now you need to fill in the Server name, User, PW and DB info so not sure if you can get past this point from the notes you posted on what SQL Express limits you to.
I'll ping the PM to see if this is something we can support.... likely answer is no if you can't fill in the info in our log on UI.
As much as I hate to suggest it but you may have to move to a Dataset. Limitation with this type of connection though...
Don
ALSO NOTE: SQL 2012 is not officially supported yet... and the Express versions usually don't work due to limitations Microsoft builds into those "lite" versions.