示例一、

表資料：

查詢結果：

方法一：

SELECT 
    t.name, 
    (SELECT SUM(h.amount) FROM test2 h WHERE h.mold = 'm1' AND h.name = t.name) m1,
    (SELECT SUM(h.amount) FROM test2 h WHERE h.mold = 'm2' AND h.name = t.name) m2,
    (SELECT SUM(h.amount) FROM test2 h WHERE h.mold = 'm3' AND h.name = t.name) m3
FROM
 
 test2 t 
GROUP BY t.name

方法二：

SELECT 
    t.name, 
    SUM(CASE WHEN t.mold='m1' THEN t.amount END) m1,
    SUM(CASE WHEN t.mold='m2' THEN t.amount END) m2,
    SUM(CASE WHEN t.mold='m3' THEN t.amount END) m3
FROM test2 t
GROUP BY t.name

例項二、

表資料：

查詢結果：

-- 靜態SQL,指課程只有語文、數學、英語這三門課程。

方法一：

SELECT 
    t.name,
    MAX(CASE t.course WHEN '語文' THEN t.score ELSE 0 END) yw,
    MAX(CASE t.course WHEN '數學' THEN t.score ELSE 0 END) sx,
    MAX(CASE t.course WHEN '英語' THEN t.score ELSE 0 END) yy
FROM test3 t
GROUP BY t.name

方法二：

SELECT 
    t.name,
    SUM(IF(course = '語文', score, 0)) yw,
    SUM
 
(IF(course = '數學', score, 0))  sx,
    SUM(IF(course = '英語', score, 0))  yy
FROM test3 t
GROUP BY t.name

建表語句及資料：

CREATE TABLE `test2` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) DEFAULT NULL COMMENT '名字',
  `mold` varchar(32) DEFAULT NULL COMMENT '型別',
  `amount` int(11) DEFAULT NULL COMMENT '數量',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;

insert into `test2` (`id`, `name`, `mold`, `amount`) values('1','小白','m1','1');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('2','小白','m2','2');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('3','小白','m3','3');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('4','小黑','m1','4');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('5','小黑','m2','5');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('6','小白','m1','6');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('7','小白','m3','7');
insert into `test2` (`id`, `name`, `mold`, `amount`) values('8','小黑','m3','1');

CREATE TABLE `test3` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) DEFAULT NULL COMMENT '姓名',
  `course` varchar(32) DEFAULT NULL COMMENT '課程',
  `score` int(11) DEFAULT NULL COMMENT '成績',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

insert into `test3` (`id`, `name`, `course`, `score`) values('1','小白','語文','99');
insert into `test3` (`id`, `name`, `course`, `score`) values('2','小白','數學','88');
insert into `test3` (`id`, `name`, `course`, `score`) values('3','小白','英語','84');
insert into `test3` (`id`, `name`, `course`, `score`) values('4','小黑','語文','89');
insert into `test3` (`id`, `name`, `course`, `score`) values('5','小黑','數學','95');
insert into `test3` (`id`, `name`, `course`, `score`) values('6','小黑','英語','98');