Union the same tables : Union « Select Clause « SQL / MySQL






  1. SQL / MySQL
  2. Select Clause
  3. Union

Union the same tables

   
mysql>
mysql> CREATE   TABLE COMMITTEE_MEMBERS
    ->         (EmployeeNO       INTEGER      NOT NULL,
    ->          BEGIN_DATE     DATE         NOT NULL,
    ->          END_DATE       DATE                 ,
    ->          POSITION       CHAR(20)             ,
    ->          PRIMARY KEY    (EmployeeNO, BEGIN_DATE));
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  6, '1990-01-01', '1990-12-31', 'Secretary');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  6, '1991-01-01', '1992-12-31', 'Member');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  6, '1992-01-01', '1993-12-31', 'Treasurer');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  6, '1993-01-01',  NULL, 'Chairman');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  2, '1990-01-01', '1992-12-31', 'Chairman');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  2, '1994-01-01',  NULL, 'Member');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (112, '1992-01-01', '1992-12-31', 'Member');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (112, '1994-01-01',  NULL, 'Secretary');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  8, '1990-01-01', '1990-12-31', 'Treasurer');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  8, '1991-01-01', '1991-12-31', 'Secretary');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  8, '1993-01-01', '1993-12-31', 'Member');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES (  8, '1994-01-01',  NULL, 'Member');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES ( 57, '1992-01-01', '1992-12-31', 'Secretary');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES ( 27, '1990-01-01', '1990-12-31', 'Member');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES ( 27, '1991-01-01', '1991-12-31', 'Treasurer');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES ( 27, '1993-01-01', '1993-12-31', 'Treasurer');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO COMMITTEE_MEMBERS VALUES ( 95, '1994-01-01',  NULL, 'Treasurer');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> SELECT   EmployeeNO, BEGIN_DATE
    -> FROM     COMMITTEE_MEMBERS
    -> UNION
    -> SELECT   EmployeeNO, END_DATE
    -> FROM     COMMITTEE_MEMBERS
    -> ORDER BY EmployeeNO;
+------------+------------+
| EmployeeNO | BEGIN_DATE |
+------------+------------+
|          2 | 1992-12-31 |
|          2 | 1990-01-01 |
|          2 | NULL       |
|          2 | 1994-01-01 |
|          6 | 1990-12-31 |
|          6 | 1992-12-31 |
|          6 | 1993-12-31 |
|          6 | NULL       |
|          6 | 1990-01-01 |
|          6 | 1991-01-01 |
|          6 | 1992-01-01 |
|          6 | 1993-01-01 |
|          8 | 1990-12-31 |
|          8 | 1991-12-31 |
|          8 | 1993-12-31 |
|          8 | 1990-01-01 |
|          8 | NULL       |
|          8 | 1991-01-01 |
|          8 | 1993-01-01 |
|          8 | 1994-01-01 |
|         27 | 1993-01-01 |
|         27 | 1990-12-31 |
|         27 | 1991-12-31 |
|         27 | 1990-01-01 |
|         27 | 1993-12-31 |
|         27 | 1991-01-01 |
|         57 | 1992-01-01 |
|         57 | 1992-12-31 |
|         95 | 1994-01-01 |
|         95 | NULL       |
|        112 | 1992-01-01 |
|        112 | 1994-01-01 |
|        112 | 1992-12-31 |
|        112 | NULL       |
+------------+------------+
34 rows in set (0.00 sec)

mysql>
mysql> drop table committee_members;
Query OK, 0 rows affected (0.00 sec)

mysql>








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