Question

我知道在MySQL上，我们可以通过为每个表赋予自己的别名来两次连接同一张表，但这似乎不适用于Access。

例如：

SELECT d.departmentID, d.depName, d.location, c1.memberID, c1.fullName,  c1.reportsTo, c2.fullName
FROM Departments as d
INNER JOIN Contacts as c1
   ON c1.departmentID = d.departmentID
INNER JOIN Contacts as c2
   ON c1.reprtsTo = c2.memberID

这样做给我一个语法错误。有谁知道我可以如何加入同一张表（“联系人”）以获取成员向其报告的人的名字（c2.fullName）？

更新，我遇到的错误：

查询表达式“ c1.departmentID = d.departmentID INNER JOIN”中的语法错误（缺少运算符），联系人作为c2 ON c1.reportsTo = c2.memberI'。

Answer 1

在MS Access中，多个JOIN需要使用括号配对：

SELECT d.departmentID, d.depName, d.location, c1.memberID, 
       c1.fullName,  c1.reportsTo, c2.fullName
FROM (Contacts as c1
INNER JOIN Departments as d
   ON c1.departmentID = d.departmentID)
INNER JOIN Contacts as c2
   ON c1.reprtsTo = c2.memberID

Answer 2

只需将表拖入可视编辑器两次。它会自动将表的第二个实例重命名为“ _1”。

SELECT Contacts.EmpID, Contacts_1.EmpID AS reportsTo
FROM Contacts INNER JOIN Contacts AS Contacts_1 ON Contacts.SupervisorID= 
Contacts_1.EmpID;

Answer 3

在这种情况下，让Access设计编辑器处理联接和别名会更容易。
以下代码基于您的代码，但由设计编辑器创建：

SELECT 
  Departments.departmentID, Departments.depName, Departments.location, 
  Contacts.memberID, Contacts.fullName, Contacts_1.reportsTo, Contacts_1.fullName
FROM (
  Departments INNER JOIN Contacts ON Departments.departmentID = Contacts.departmentID
) INNER JOIN Contacts AS Contacts_1 ON Contacts.reportsTo = Contacts_1.memberID;

如何在Access上两次连接同一张表

3 个答案: