SQL學(xué)習(xí)筆記五去重,給新加字段賦值的方法
更新時(shí)間:2011年08月28日 22:28:31 作者:
SQL學(xué)習(xí)筆記五去重,給新加字段賦值的方法,需要的朋友可以參考下。
去掉數(shù)據(jù)重復(fù)
增加兩個(gè)字段
alter TABLE T_Employee Add FSubCompany VARchar(20);
ALTER TABLE T_Employee ADD FDepartment VARCHAR(20);
給新加的字段賦值
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';
查詢并去重
select distinct FDepartment from T_Employee
select distinct FDepartment,FSubCompany from T_Employee
增加兩個(gè)字段
alter TABLE T_Employee Add FSubCompany VARchar(20);
ALTER TABLE T_Employee ADD FDepartment VARCHAR(20);
給新加的字段賦值
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';
查詢并去重
select distinct FDepartment from T_Employee
select distinct FDepartment,FSubCompany from T_Employee
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