The syntax of the MINUS clause is as follows:
select_statement MINUS select_statement
select_statement
is a SELECT
statement that does not contain an ORDER
BY
or FOR UPDATE
clause.
The MINUS
operator computes the set of rows that are in the result of the left SELECT
statement but not in the result of the right one.
The result of the MINUS
clause does not contain duplicate rows.
Unless otherwise specified in parentheses, multiple MINUS
operators in the same SELECT
statement are evaluated from left to right. The MINUS
clause binds at the same level as the UNION
clause.