错误1060 (42S21)：重复列名'eid‘

Question

我正在试图弄清楚为什么在这个查询中我会得到一个重复的列名。我觉得我是正确的前缀我的搜索条件，不应该得到这个错误。请给我建议。

模型

Emp(eid:integer, ename:varchar, age:integer, salary:integer)
Works(did:integer, eid:integer)
Dept(did:integer, managerid:integer) //managerid is foreign key to eid

查询

CREATE VIEW Manager AS
SELECT e.eid, e.ename, e2.eid, e2.ename
FROM Emp AS e,
    Dept AS d
        LEFT JOIN Emp AS e2 ON d.managerid = e2.eid;

Answer 1

在你的领域里试试化名。见下文：

CREATE VIEW Manager AS
SELECT 
      e.eid AS eid1, 
      e.ename AS ename1, 
      e2.eid AS eid2, 
      e2.ename AS ename2
FROM Emp AS e,
    Dept AS d
LEFT JOIN Emp AS e2 ON d.managerid = e2.eid2;