匿名通过本文主要向大家介绍了新加字段,赋值等相关知识,希望本文的分享对您有所帮助
SQL学习笔记五去重，给新加字段赋值的方法，需要的朋友可以参考下。
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