SQL>
SQL> create table x (c1 number);
Table created.
SQL>
SQL> create table y (c1 number);
Table created.
SQL>
SQL> Insert into x values (1);
1 row created.
SQL> Insert into x values (2);
1 row created.
SQL> Insert into x values (3);
1 row created.
SQL> Insert into x values (4);
1 row created.
SQL> Insert into x values (5);
1 row created.
SQL> Insert into x values (6);
1 row created.
SQL>
SQL>
SQL> Insert into y values (5);
1 row created.
SQL> Insert into y values (6);
1 row created.
SQL> Insert into y values (7);
1 row created.
SQL>
SQL> SELECT * FROM x
2 UNION
3 SELECT * FROM y ;
C1
----------
1
2
3
4
5
6
7
7 rows selected.
SQL>
SQL> SELECT * FROM x
2 UNION ALL
3 SELECT * FROM y ;
C1
----------
1
2
3
4
5
6
5
6
7
9 rows selected.
SQL>
SQL> drop table x;
Table dropped.
SQL> drop table y;
Table dropped.
SQL> --