Using Set Operators

The set operators combines rows returned by two or more queries. The number of columns and the column types returned by the queries must match, although the column names may be different.

Operator	Description
UNION ALL	Returns all the rows retrieved by the queries, including duplicate rows.
UNION	Returns all non-duplicate rows retrieved by the queries.
INTERSECT	Returns rows that are in both queries.
MINUS	Subtracts one set of rows from another set of rows.