本文介绍的实例成功的实现了动态行转列。下面我以一个简单的数据库为例子，说明一下。
数据表结构
这里我用一个比较简单的例子来说明，也是行转列的经典例子，就是学生的成绩
三张表：学生表、课程表、成绩表
学生表
就简单一点，学生学号、学生姓名两个字段
| CREATE TABLE `student` ( `stuid` VARCHAR(16) NOT NULL COMMENT '学号', `stunm` VARCHAR(20) NOT NULL COMMENT '学生姓名', PRIMARY KEY (`stuid`))COLLATE='utf8_general_ci'ENGINE=InnoDB; |
课程表
课程编号、课程名
| CREATE TABLE `courses` ( `courseno` VARCHAR(20) NOT NULL, `coursenm` VARCHAR(100) NOT NULL, PRIMARY KEY (`courseno`))COMMENT='课程表'COLLATE='utf8_general_ci'ENGINE=InnoDB; |
成绩表
学生学号、课程号、成绩
| CREATE TABLE `score` ( `stuid` VARCHAR(16) NOT NULL, `courseno` VARCHAR(20) NOT NULL, `scores` FLOAT NULL DEFAULT NULL, PRIMARY KEY (`stuid`, `courseno`))COLLATE='utf8_general_ci'ENGINE=InnoDB; |
以上就是数据库表的结构了，这里没有建立外键，但是根据表的结构，可以清楚的看到成绩表中的学号和课程号是与学生表、课程表分别关联起来的。
数据准备
| /*学生表数据*/Insert Into student (stuid, stunm) Values('1001', '张三');Insert Into student (stuid, stunm) Values('1002', '李四');Insert Into student (stuid, stunm) Values('1003', '赵二');Insert Into student (stuid, stunm) Values('1004', '王五');Insert Into student (stuid, stunm) Values('1005', '刘青');Insert Into student (stuid, stunm) Values('1006', '周明');/*课程表数据*/Insert Into courses (courseno, coursenm) Values('C001', '大学语文');Insert Into courses (courseno, coursenm) Values('C002', '新视野英语');Insert Into courses (courseno, coursenm) Values('C003', '离散数学');Insert Into courses (courseno, coursenm) Values('C004', '概率论与数理统计');Insert Into courses (courseno, coursenm) Values('C005', '线性代数');Insert Into courses (courseno, coursenm) Values('C006', '高等数学(一)');Insert Into courses (courseno, coursenm) Values('C007', '高等数学(二)');/*成绩表数据*/Insert Into score(stuid, courseno, scores) Values('1001', 'C001', 67);Insert Into score(stuid, courseno, scores) Values('1002', 'C001', 68);Insert Into score(stuid, courseno, scores) Values('1003', 'C001', 69);Insert Into score(stuid, courseno, scores) Values('1004', 'C001', 70);Insert Into score(stuid, courseno, scores) Values('1005', 'C001', 71);Insert Into score(stuid, courseno, scores) Values('1006', 'C001', 72);Insert Into score(stuid, courseno, scores) Values('1001', 'C002', 87);Insert Into score(stuid, courseno, scores) Values('1002', 'C002', 88);Insert Into score(stuid, courseno, scores) Values('1003', 'C002', 89);Insert Into score(stuid, courseno, scores) Values('1004', 'C002', 90);Insert Into score(stuid, courseno, scores) Values('1005', 'C002', 91);Insert Into score(stuid, courseno, scores) Values('1006', 'C002', 92);Insert Into score(stuid, courseno, scores) Values('1001', 'C003', 83);Insert Into score(stuid, courseno, scores) Values('1002', 'C003', 84);Insert Into score(stuid, courseno, scores) Values('1003', 'C003', 85);Insert Into score(stuid, courseno, scores) Values('1004', 'C003', 86);Insert Into score(stuid, courseno, scores) Values('1005', 'C003', 87);Insert Into score(stuid, courseno, scores) Values('1006', 'C003', 88);Insert Into score(stuid, courseno, scores) Values('1001', 'C004', 88);Insert Into score(stuid, courseno, scores) Values('1002', 'C004', 89);Insert Into score(stuid, courseno, scores) Values('1003', 'C004', 90);Insert Into score(stuid, courseno, scores) Values('1004', 'C004', 91);Insert Into score(stuid, courseno, scores) Values('1005', 'C004', 92);Insert Into score(stuid, courseno, scores) Values('1006', 'C004', 93);Insert Into score(stuid, courseno, scores) Values('1001', 'C005', 77);Insert Into score(stuid, courseno, scores) Values('1002', 'C005', 78);Insert Into score(stuid, courseno, scores) Values('1003', 'C005', 79);Insert Into score(stuid, courseno, scores) Values('1004', 'C005', 80);Insert Into score(stuid, courseno, scores) Values('1005', 'C005', 81);Insert Into score(stuid, courseno, scores) Values('1006', 'C005', 82);Insert Into score(stuid, courseno, scores) Values('1001', 'C006', 77);Insert Into score(stuid, courseno, scores) Values('1002', 'C006', 78);Insert Into score(stuid, courseno, scores) Values('1003', 'C006', 79);Insert Into score(stuid, courseno, scores) Values('1004', 'C006', 80);Insert Into score(stuid, courseno, scores) Values('1005', 'C006', 81);Insert Into score(stuid, courseno, scores) Values('1006', 'C006', 82); |
