Minus vs Except Difference in ORACLE/SQL Server

Question

MINUS is a SQL set operation that selects elements from the first table and then removes rows that are also returned by the second SELECT statement in Oracle. And in SQL Ser

Answer 1

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>
END
ELSE
SELECT ... <second query>

Answer 2

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)