我想用经理的名字检索员工姓名。
例如:
Employee_Lastname:WARX
Employee_Firstname:CYNTHIA
MANAGER_NANE:SMITH
Warx Cythnia 有一个 Manager_ID=7369 的经理,他是 Smith John,因为 Smith 的 Employee_ID=7369
我想创建 MANGER_NAME 列并添加数据...
我想用经理的名字检索员工姓名。
例如:
Employee_Lastname:WARX
Employee_Firstname:CYNTHIA
MANAGER_NANE:SMITH
Warx Cythnia 有一个 Manager_ID=7369 的经理,他是 Smith John,因为 Smith 的 Employee_ID=7369
我想创建 MANGER_NAME 列并添加数据...
也许您只想投影记录的值,而不是在表中添加新列,对吗?你只需要加入这个,
SELECT a.*,
b.Employee_LastName AS MANAGER_LASTNAME
FROM EmpTable a
LEFT JOIN EmpTable b
ON a.Manager_ID = b.Employee_ID
或者
SELECT a.Employee_LastName,
a.Employee_FirstName,
b.Employee_LastName AS MANAGER_LASTNAME
FROM EmpTable a
LEFT JOIN EmpTable b
ON a.Manager_ID = b.Employee_ID
通常,您不会存储此类信息。但是查询的时候可以很方便的获取:
select
t1.Employee_Lastname,
t1.Employee_Firstname,
t2.Employee_Lastname as manager_name
from [table] t1
left join
[table] t2
on
t1.manager_id = t2.employee_id