Regardless of having supportsTupleDistinctCounts returning false on the selected dialect, Hibernate tries to do a COUNT(DISTINCT col1_, col2_) and the JDBC driver throws a Incorrect syntax near ',' exception.

I suppose this is a limitation of SQL Server, but in my opinion this should not throw an exception and also it should be somehow possible to instruct the dialect to replace the COUNT(DISTINCT col1_, col2_) syntax with a COUNT(DISTINCT CHECKSUM(col1_, col2_)) which may work event in SQL Server.

This was initially discussed within HHH-7165 Closed .