Set Operators

Set operators combine the results of two component queries into a single result. Queries containing set operators are called compound queries. Table 4-5 lists the SQL set operators. They are fully described with examples in The Set Operators.

Table 4-5 Set Operators

Operator Returns

UNION

All distinct rows selected by either query

UNION ALL

All rows selected by either query, including duplicates

INTERSECT

All distinct rows selected by both queries

INTERSECT ALL

All rows selected by both queries including duplicates

MINUS

All distinct rows selected by the first query but not the second

MINUS ALL

All rows selected by the first query but not the second including duplicates

EXCEPT

All distinct rows selected by the first query but not the second

EXCEPT ALL

All rows selected by the first query but not the second including duplicates