MySQL queries to get the top three student information for each class score

Today, some colleagues talked about how to find the MySQL query to get the top three students of each class, in the online search, and then write code, and soon OK.

CREATE TABLE t_testscore (pk_id int PRIMARY KEY, C_name VARCHAR (), C_score int, c_class int) DEFAULT Charse T=utf8;

INSERT into T_testscore VALUES (1, ' 36 ', 66, 1), (2, ' Zhang 35 ', 65, 1), (3, ' 34 ', 64, 1), (4, ' 33 ', 63, 1), (5, ' 32 ', 62, 1);

INSERT into T_testscore VALUES (11, ' Li 46 ', 76, 2), (12, ' Li 45 ', 75, 2), (13, ' Li 44 ', 74, 2), (14, ' Li 43 ', 73, 2), (15, ' Li 42 ', 72 , 2);

SELECT * from T_testscore t

where EXISTS (SELECT COUNT (*) from T_testscore ts WHERE ts.c_score>=t.c_score GROUP by Ts.c_class have COUNT (*) < =3)

ORDER by C_class,c_score DESC;

MySQL queries to get the top three student information for each class score