/*
mysql> /* Number of animals per sex: */
mysql> SELECT sex, COUNT(*) FROM Bird GROUP BY sex;
+------+----------+
| sex | COUNT(*) |
+------+----------+
| f | 1 |
| m | 2 |
+------+----------+
2 rows in set (0.00 sec)
*/
Drop table Bird;
CREATE TABLE Bird (
name VARCHAR(20),
owner VARCHAR(20),
species VARCHAR(20),
sex CHAR(1),
birth DATE,
death DATE
);
INSERT INTO Bird VALUES ('BlueBird','Joe','Car','f','1999-03-30',NULL);
INSERT INTO Bird VALUES ('RedBird','Yin','Bus','m','1979-04-30',1998-01-30);
INSERT INTO Bird VALUES ('RedBird','Yin','Bus','m','1998-01-30',NULL);
/* Number of animals per sex: */
SELECT sex, COUNT(*) FROM Bird GROUP BY sex;