To determine how many drivers were on the road and how many miles were driven each day : SUM « Aggregate Functions « SQL / MySQL

1. SQL / MySQL
2. Aggregate Functions
3. SUM

To determine how many drivers were on the road and how many miles were driven each day

      
mysql>
mysql> CREATE TABLE mytable
    -> (
    ->  rec_id          INT UNSIGNED NOT NULL AUTO_INCREMENT,
    ->  name            VARCHAR(20) NOT NULL,
    ->  trav_date       DATE NOT NULL,
    ->  miles           INT NOT NULL,
    ->  PRIMARY KEY (rec_id)
    -> );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> INSERT INTO mytable (name,trav_date,miles)
    ->  VALUES
    ->          ('Ben','2010-11-30',152),
    ->          ('Suzi','2010-11-29',391),
    ->          ('Henry','2010-11-29',300),
    ->          ('Henry','2010-11-27',96),
    ->          ('Ben','2010-11-29',131),
    ->          ('Henry','2010-11-26',115),
    ->          ('Suzi','2010-12-02',502),
    ->          ('Henry','2010-12-01',197),
    ->          ('Ben','2010-12-02',79),
    ->          ('Henry','2010-11-30',203)
    -> ;
Query OK, 10 rows affected (0.00 sec)
Records: 10  Duplicates: 0  Warnings: 0

mysql>
mysql> SELECT trav_date,
    -> COUNT(*) AS 'number of drivers', SUM(miles) As 'miles logged'
    -> FROM mytable GROUP BY trav_date;
+------------+-------------------+--------------+
| trav_date  | number of drivers | miles logged |
+------------+-------------------+--------------+
| 2010-11-26 |                 1 |          115 |
| 2010-11-27 |                 1 |           96 |
| 2010-11-29 |                 3 |          822 |
| 2010-11-30 |                 2 |          355 |
| 2010-12-01 |                 1 |          197 |
| 2010-12-02 |                 2 |          581 |
+------------+-------------------+--------------+
6 rows in set (0.00 sec)

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

mysql>

   
    
    
    
    
    
  

Related examples in the same category