Mega Code Archive
COUNT() and GROUP BY
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/*
mysql> /* COUNT() and GROUP BY
mysql> Number of animals per species:
mysql> */
mysql> SELECT species, COUNT(*) FROM Bird GROUP BY species;
+---------+----------+
| species | COUNT(*) |
+---------+----------+
| Bus | 2 |
| Car | 1 |
+---------+----------+
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);
/* COUNT() and GROUP BY
Number of animals per species:
*/
SELECT species, COUNT(*) FROM Bird GROUP BY species;
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