Set operators
- Last Updated: May 12, 2026
- 1 minute read
- OpenAccess SDK
- Version 8.1
- Documentation
Set operators combine the results of two component queries into a single result. Queries containing set operators are called compound queries. The following table describes the supported set operators.
Set operators
| Operator | Returns |
| UNION | All rows selected by either query. |
| UNION ALL | All rows selected by either query, including all duplicates. |
Examples
SELECT deptno FROM emp UNION SELECT deptno FROM dept
SELECT deptno FROM emp UNION ALL SELECT deptno FROM dept