Assign the result of an aggregate function to a variable : Variable « Select Clause « SQL / MySQL






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

Assign the result of an aggregate function to a variable

       
mysql>
mysql>
mysql> CREATE   TABLE PENALTIES
    ->         (PAYMENTNO      INTEGER      NOT NULL,
    ->          EmployeeNO       INTEGER      NOT NULL,
    ->          PAYMENT_DATE   DATE         NOT NULL,
    ->          AMOUNT         DECIMAL(7,2) NOT NULL,
    ->          PRIMARY KEY    (PAYMENTNO)          );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> INSERT INTO PENALTIES VALUES (1,  6, '1980-12-08',100);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (2, 44, '1981-05-05', 75);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (3, 27, '1983-09-10',100);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (4,104, '1984-12-08', 50);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (5, 44, '1980-12-08', 25);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (6,  8, '1980-12-08', 25);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (7, 44, '1982-12-30', 30);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (8, 27, '1984-11-12', 75);
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> SELECT   @PENALTIESTOTAL := SUM(AMOUNT),
    ->          @NUMBERPENALTIES := COUNT(*)
    -> FROM     PENALTIES;
+--------------------------------+------------------------------+
| @PENALTIESTOTAL := SUM(AMOUNT) | @NUMBERPENALTIES := COUNT(*) |
+--------------------------------+------------------------------+
|                         480.00 |                            8 |
+--------------------------------+------------------------------+
1 row in set (0.00 sec)

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

mysql>








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