Question

我在制作此内部联接查询时遇到了麻烦

原件：

SELECT *
FROM (
    SELECT *, row_number() OVER (PARTITION BY idmicro ORDER BY IdHistMov desc) AS rownum
    FROM dbo.T_HistMovEquip
    ) AS initialResultSet
WHERE initialResultSet.rownum<=2

尝试内连接：

SELECT *
FROM (
    SELECT *, row_number() OVER (PARTITION BY c.idmicro ORDER BY c.IdHistMov desc) AS rownum
    FROM dbo.T_HistMovEquip c
    INNER JOIN T_Micro m ON c.Idmicro=m.Idmicro
    ) AS initialResultSet
WHERE initialResultSet.rownum<=2

出现此错误：列＆＃39; IDMicro＆＃39;已经多次为＆quot; initialResultSet＆＃39;。

指定

谢谢！

Answer 1

为什么不只指定所需的列。像这样：

SELECT *
FROM (
    SELECT 
        c.idmicro, 
        c.IdHistMov,
        /*And so on*/
        row_number() OVER (PARTITION BY c.idmicro ORDER BY c.IdHistMov desc) AS rownum
    FROM 
        dbo.T_HistMovEquip c
        INNER JOIN T_Micro m 
            ON c.Idmicro=m.Idmicro
    ) AS initialResultSet
WHERE initialResultSet.rownum<=2

Answer 2

那是因为你明确地在两个表中都有相同的列名（IDMicro）时使用Select *。尝试将输出选择“过滤”为仅您感兴趣的列，或者如果您需要两个表中的相同列名，请使用列别名。

如何在此查询中进行内部联接

2 个答案: