Mega Code Archive
To determine how many drivers were on the road and how many miles were driven each day
<![CDATA[
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>
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