mysql>
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(trav_date)
-> FROM mytable
-> GROUP BY trav_date
-> HAVING COUNT(trav_date) = 1;
+------------+------------------+
| trav_date | COUNT(trav_date) |
+------------+------------------+
| 2010-11-26 | 1 |
| 2010-11-27 | 1 |
| 2010-12-01 | 1 |
+------------+------------------+
3 rows in set (0.00 sec)
mysql>
mysql> SELECT trav_date, COUNT(trav_date)
-> FROM mytable
-> GROUP BY trav_date
-> HAVING COUNT(trav_date) > 1;
+------------+------------------+
| trav_date | COUNT(trav_date) |
+------------+------------------+
| 2010-11-29 | 3 |
| 2010-11-30 | 2 |
| 2010-12-02 | 2 |
+------------+------------------+
3 rows in set (0.00 sec)
mysql>
mysql> drop table mytable;
Query OK, 0 rows affected (0.00 sec)