Minus vs Except Difference in ORACLE/SQL Server
There is no difference between Oracle MINUS and SQL Server EXCEPT.
They are intended to do the same thing.
- http://dotnetguts.blogspot.com/2008/04/minus-keyword-in-sql-server.html
- http://blog.sqlauthority.com/2008/08/07/sql-server-except-clause-in-sql-server-is-similar-to-minus-clause-in-oracle/
- http://vyaskn.tripod.com/oracle_sql_server_differences_equivalents.htm (search for MINUS operator), read the description, which matches EXCEPT for SQL Server exactly)
- Oracle MINUS vs SQL Server EXCEPT (compare docs)
This will check for any result set from the first query, then run the except if there is a result. If not it only runs the second query.
IF EXISTS (SELECT NULL FROM ... <first query criteria> WHERE ...)BEGIN SELECT ... <first query> EXCEPT SELECT ... <second query>ENDELSESELECT ... <second query>