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SQL学习笔记五去重,给新加字段赋值的方法

时间:2016-01-01 14:38:35      阅读:202      评论:0      收藏:0      [点我收藏+]
去掉数据重复
增加两个字段
alter TABLE T_Employee Add FSubCompany VARchar(20);
ALTER TABLE T_Employee ADD FDepartment VARCHAR(20);

给新加的字段赋值
UPDATE T_Employee SET FSubCompany=‘Beijing‘,FDepartment=‘Development‘ where FNumber=‘DEV001‘;
UPDATE T_Employee SET FSubCompany=‘ShenZhen‘,FDepartment=‘Development‘ where FNumber=‘DEV002‘;
UPDATE T_Employee SET FSubCompany=‘Beijing‘,FDepartment=‘HumanResource‘ where FNumber=‘HR001‘;
UPDATE T_Employee SET FSubCompany=‘Beijing‘,FDepartment=‘HumanResource‘ where FNumber=‘HR002‘;
UPDATE T_Employee SET FSubCompany=‘Beijing‘,FDepartment=‘InfoTech‘ where FNumber=‘IT001‘;
UPDATE T_Employee SET FSubCompany=‘ShenZhen‘,FDepartment=‘InfoTech‘ where FNumber=‘IT002‘;
UPDATE T_Employee SET FSubCompany=‘Beijing‘,FDepartment=‘Sales‘ where FNumber=‘SALES001‘;
UPDATE T_Employee SET FSubCompany=‘Beijing‘,FDepartment=‘Sales‘ where FNumber=‘SALES002‘;
UPDATE T_Employee SET FSubCompany=‘ShenZhen‘,FDepartment=‘Sales‘ where FNumber=‘SALES003‘;

查询并去重
select distinct FDepartment from T_Employee

select distinct FDepartment,FSubCompany from T_Employee

SQL学习笔记五去重,给新加字段赋值的方法

原文:http://www.jb51.net/article/28144.htm

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