Combine data from one or more SELECT statements.
In Oracle 8i and above the UNION command has been supplemented by the
new Analytic Features
Syntax:
SELECT command {UNION | UNION ALL | INTERSECT | MINUS} SELECT command
key:
UNION - Combine the unique rows returned by 2 SELECT statements
UNION ALL - Combine the rows returned by 2 SELECT statements (including all duplicates)
INTERSECT - Return only those rows that are in *both* SELECT statements
MINUS - Return the rows that are in the first SELECT but not the second
To combine more than two SELECTs nest the expressions:
SELECT expr1 UNION (SELECT expr2 UNION SELECT expr3)
Related Oracle Commands:
SELECT - Retrieve data from one or more tables, views, or snapshots.
Related Views:
DBA_ALL_TABLES ALL_ALL_TABLES USER_ALL_TABLES DBA_TABLES ALL_TABLES USER_TABLES TAB DBA_VIEWS ALL_VIEWS USER_VIEWS DICTIONARY DICT_COLUMNS