MySql表数据行列转换

USE test;

CREATE TABLE student(

id VARCHAR(20) NOT NULL,

subjects VARCHAR(20) NOT NULL,

grade INTEGER NOT NULL DEFAULT 0

);

INSERT INTO student VALUES('student1','语文',80);

INSERT INTO student VALUES('student1','数学',70);

INSERT INTO student VALUES('student1','英语',60);

INSERT INTO student VALUES('student2','语文',90);

INSERT INTO student VALUES('student2','数学',80);

INSERT INTO student VALUES('student2','英语',100);

COMMIT;

SELECT * FROM student;

id subjects grade

student1 语文 80

student1 数学 70

student1 英语 60

student2 语文 90

student2 数学 80

student2 英语 100

/* 行列转换*/

SELECT

id,

SUM(IF(subjects='语文',grade,NULL)) '语文',

SUM(IF(subjects='数学',grade,NULL)) '数学',

SUM(IF(subjects='英语',grade,NULL)) '英语'

FROM

student

GROUP BY

id

;

id 语文 数学 英语

student1 80 70 60

student2 90 80 100