别名

Question

我对下一个SQL查询有问题（由sequelize ORM生成）：

SELECT 
    "Publication".*, 
    "user"."id" AS "user.id"
FROM 
    (SELECT "Publication"."club_id" AS "clubId", "Publication"."user_id" AS "userId" FROM "publication" AS "Publication" WHERE ("Publication"."club_id" = '1')) AS "Publication" 
    LEFT OUTER JOIN "user_account" AS "user" ON "Publication"."user_id" = "user"."id";

产生的错误是：

  

错误：列Publication.user_id不存在

     

第6行：LEFT OUTER JOIN“user_account”AS“user”ON“Publication”。“...                                                            ^

我对正在发生的事情的直觉是"Publication"."user_id"被别名为userId。然后，查询被别名为"Publication"（覆盖之前引用该表的标签）。左外连接尝试将新Publication user_id属性与user.id匹配，但它无法使用，因为现在它被称为userId。

我是否正确理解了这个问题？

Answer 1

  

错误：列 Publication.user_id 不存在

答案很简单user_id＆lt;＆gt; userId：

SELECT "Publication".*, 
       "user"."id" AS "user.id"
FROM 
    (SELECT "Publication"."club_id"  AS "clubId"
            ,"Publication"."user_id" AS "userId" 
      FROM "publication" AS "Publication" 
     WHERE "Publication"."club_id" = '1') AS "Publication" 
LEFT JOIN "user_account" AS "user" 
  ON "Publication"."userId" = "user"."id";
                    -- here use column's alias