Group by two columns : Group « Select Clause « SQL / MySQL






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  2. Select Clause
  3. Group

Group by two columns

      
mysql>
mysql>
mysql> CREATE   TABLE MATCHES
    ->         (MATCHNO        INTEGER      NOT NULL,
    ->          TEAMNO         INTEGER      NOT NULL,
    ->          EmployeeNO       INTEGER      NOT NULL,
    ->          WON            SMALLINT     NOT NULL,
    ->          LOST           SMALLINT     NOT NULL,
    ->          PRIMARY KEY    (MATCHNO)            );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> INSERT INTO MATCHES VALUES ( 1, 1,   6, 3, 1);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 2, 1,   6, 2, 3);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 3, 1,   6, 3, 0);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 4, 1,  44, 3, 2);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 5, 1,  83, 0, 3);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 6, 1,   2, 1, 3);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 7, 1,  57, 3, 0);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 8, 1,   8, 0, 3);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES ( 9, 2,  27, 3, 2);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES (10, 2, 104, 3, 2);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES (11, 2, 112, 2, 3);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES (12, 2, 112, 1, 3);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO MATCHES VALUES (13, 2,   8, 0, 3);
Query OK, 1 row affected (0.00 sec)

mysql>
mysql>
mysql> SELECT   TEAMNO, EmployeeNO
    -> FROM     MATCHES
    -> GROUP BY TEAMNO, EmployeeNO
    -> ;
+--------+------------+
| TEAMNO | EmployeeNO |
+--------+------------+
|      1 |          2 |
|      1 |          6 |
|      1 |          8 |
|      1 |         44 |
|      1 |         57 |
|      1 |         83 |
|      2 |          8 |
|      2 |         27 |
|      2 |        104 |
|      2 |        112 |
+--------+------------+
10 rows in set (0.00 sec)

mysql>
mysql> SELECT   TEAMNO, EmployeeNO
    -> FROM     MATCHES
    -> GROUP BY EmployeeNO, TEAMNO
    -> ;
+--------+------------+
| TEAMNO | EmployeeNO |
+--------+------------+
|      1 |          2 |
|      1 |          6 |
|      1 |          8 |
|      2 |          8 |
|      2 |         27 |
|      1 |         44 |
|      1 |         57 |
|      1 |         83 |
|      2 |        104 |
|      2 |        112 |
+--------+------------+
10 rows in set (0.00 sec)

mysql>
mysql> SELECT   TEAMNO, EmployeeNO, SUM(WON),
    ->          COUNT(*), MIN(LOST)
    -> FROM     MATCHES
    -> GROUP BY TEAMNO, EmployeeNO;
+--------+------------+----------+----------+-----------+
| TEAMNO | EmployeeNO | SUM(WON) | COUNT(*) | MIN(LOST) |
+--------+------------+----------+----------+-----------+
|      1 |          2 |        1 |        1 |         3 |
|      1 |          6 |        8 |        3 |         0 |
|      1 |          8 |        0 |        1 |         3 |
|      1 |         44 |        3 |        1 |         2 |
|      1 |         57 |        3 |        1 |         0 |
|      1 |         83 |        0 |        1 |         3 |
|      2 |          8 |        0 |        1 |         3 |
|      2 |         27 |        3 |        1 |         2 |
|      2 |        104 |        3 |        1 |         2 |
|      2 |        112 |        3 |        2 |         3 |
+--------+------------+----------+----------+-----------+
10 rows in set (0.00 sec)

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








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