在表中找到列时的未知列

Question

我遇到了未知子句错误，无法弄明白。我对SQL有点绿，但不是完全绿色。这是我的代码。

SELECT tg.name, tg.current_amount, tg.priority, tgc.needed, tgh.date
FROM  tb_goal tg, tb_goal_college tgc, tb_goal_home tgh 
CROSS JOIN (
    SELECT tgc.needed, tgc.id, tgc.goal_id 
    FROM tb_goal_college tgc, tb_goal tg
) AS T ON tg.id = T.id

我在'on子句'中收到了Unknown column tg，=。id的错误。

该列存在于tg中，我没有看到问题。

请帮忙。

谢谢。

Answer 1

请试试这个

SELECT tg.name, tg.current_amount, tg.priority, tgc.needed, tgh.date
FROM   tb_goal_college tgc, tb_goal_home tgh ,tb_goal tg
CROSS JOIN (
   SELECT tgc.needed, tgc.id, tgc.goal_id 
   FROM tb_goal_college tgc, tb_goal a
   ) AS T ON tg.id = T.id