多部分标识符无法绑定但没有连接问题？

Question

我在MS Server Management studio v11.02上运行以下但是'我收到一个错误说:

The multi-part identifier "PO.LastPo" could not be bound.

我能做些什么来解决这个问题？

SELECT DISTINCT PO.LastPo
    INTO #IncludedPoll
    FROM
    (
            -- Inner query makes sure member was actually enrolled for 2 yrs
            SELECT LastPo, COUNT(*) AS Periods
            FROM [Cye].[2_output_lastPoll] PO
            WHERE PO.PollPq IN (1,2)
            GROUP BY LastPo
    ) A
    WHERE Periods IN (1,2) AND A.LastPo NOT IN (SELECT LastPo FROM #FilterPoll)

#FilterPoll是一个临时表,我很好,并包含一些我想从#IncludedPoll临时表中过滤掉的ID .

我已经看过其他答案,但它们都与连接有关,这不应该是问题.

Answer 1

你命名了你的内部查询A,所以它应该SELECT DISTINCT A.LastPo代替PO.LastPo