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加入查询以从2个表中选择字段

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我创建了3个表,即员工,部门和EmpDept .

1)员工表字段是

: - EmployeeID(主键),Fname,Lname,年龄,薪水,地址

2)部门表字段是: -

DepartmentID(主键),DeptName,DeptLocation

3)EmpDept表字段是: -

ID(主键),EmpId(Foriegn Key引用Employee表),DeptID(外键引用Department表)

我想执行以下操作: -

a)从表Employee和Department中选择所有字段
b)删除特定部门还会删除属于该特定部门的员工表中的所有员工 .

我没有得到第3表中包含哪些字段(即EmpDept)以及如何应用连接来选择列

我的尝试

create procedure EmpDept2 
as 
Begin 
select Employees.EmployeeID
      , Employees.FirstName
      , Employees.LastName
      , Employees.Age
      , Employees.CreatedDate
      , Employees.LastModifiedDate
      , Employees.ModifiedBy
      , Employees.Active
      ,Department.DepartmentID
      , Department.DeptName 
from Employees, Department inner join EmpDept 
on EmpDept.EmpId = Employees.EmployeeID 
on EmpDept.DeptId= Department.DepartmentID

1 回答

  • 1
    create procedure EmpDept2 
    as 
    Begin 
    select Employees.EmployeeID
          , Employees.FirstName
          , Employees.LastName
          , Employees.Age
          , Employees.CreatedDate
          , Employees.LastModifiedDate
          , Employees.ModifiedBy
          , Employees.Active
          ,Department.DepartmentID
          , Department.DeptName 
    from Employees inner join EmpDept 
    on EmpDept.EmpId = Employees.EmployeeID 
    inner join Department 
    on EmpDept.DeptId= Department.DepartmentID
    END
    

    JOIN一次两个表,然后条件ON你正在加入它们的内容,然后再一个一个地添加其他表,指定你想要加入它们的条件 .

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