Only the SELECT and INSERT-SELECT SQL statements can use the set operators UNION, INTERSECT, and MINUS/EXCEPT. The set operators enable you to manipulate the answers to two or more queries by combining the results of each query into a single result set.
The set operators can also be used within these operations:
- View definitions
- Derived tables
- Subqueries
- INSERT … SELECT statements
You cannot use the set operators with LOB columns.