COUNT() and GROUP BY

/*

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;


           
       

[출처] http://www.java2s.com/Code/SQL/Select-Clause/COUNTandGROUPBY.htm

경축! 아무것도 안하여 에스천사게임즈가 새로운 모습으로 재오픈 하였습니다.
어린이용이며, 설치가 필요없는 브라우저 게임입니다.
https://s1004games.com