联合结果集
新建临时工数据表
复制代码 代码如下:
CREATE TABLE T_TempEmployee (FIdCardNumber VARCHAR(20),FName VARCHAR(20),FAge int,PRIMARY KEY(FIdCardNumber));
INSERT INTO T_TempEmployee(FIdCardNumber,FName,FAge) VALUES(‘1234567890121′,’Sarani’,33);
INSERT INTO T_TempEmployee(FIdCardNumber,FName,FAge) VALUES(‘1234567890122′,’Tom’,26);
INSERT INTO T_TempEmployee(FIdCardNumber,FName,FAge) VALUES(‘1234567890123′,’Yalaha’,38);
INSERT INTO T_TempEmployee(FIdCardNumber,FName,FAge) VALUES(‘1234567890124′,’Tina’,26);
INSERT INTO T_TempEmployee(FIdCardNumber,FName,FAge) VALUES(‘1234567890125′,’Konkaya’,29);
INSERT INTO T_TempEmployee(FIdCardNumber,FName,FAge) VALUES(‘1234567890126′,’Fotifa’,46);
Union联合
复制代码 代码如下:
select FNumber,FAge from T_Employee
union
select FIdCardNumber,FAge from T_TempEmployee
union上下的查询个数和类型必须对应一致
复制代码 代码如下:
select FNumber,FAge,FDepartment from T_Employee
union
select FIdCardNumber,FAge ,’临时工，无部门’ from T_TempEmployee
union默认将重复数据去掉。如果不让他去掉，则用union all
复制代码 代码如下:
select FName from T_Employee
union all
select FName from T_TempEmployee
原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/233989.html