sql 2005 - 该列已指定多次 [英] sql 2005 - The column was specified multiple times

问题描述

在sql 2005中尝试运行此查询时，我收到以下错误：

I am getting the following error when trying to run this query in sql 2005:

    SELECT tb.*
    FROM (
        SELECT * 
        FROM vCodesWithPEs INNER JOIN vDeriveAvailabilityFromPE 
        ON vCodesWithPEs.PROD_PERM = vDeriveAvailabilityFromPE.PEID 
        INNER JOIN PE_PDP ON vCodesWithPEs.PROD_PERM = PE_PDP.PEID
    ) AS tb;

Error: The column 'PEID' was specified multiple times for 'tb'.

我是sql的新用户。提前感谢您的建议。

I am new to sql. Thank You in advance for your advise.

Eneo。

推荐答案

如上所述，问题是你从两个表中选择PEID，解决方案是指定你想要的PEID，例如

The problem, as mentioned, is that you are selecting PEID from two tables, the solution is to specify which PEID do you want, for example

 SELECT tb.*
    FROM (
        SELECT tb1.PEID,tb2.col1,tb2.col2,tb3.col3 --, and so on
        FROM vCodesWithPEs as tb1 INNER JOIN vDeriveAvailabilityFromPE as tb2
        ON tb1.PROD_PERM = tb2.PEID 
        INNER JOIN PE_PDP tb3 ON tb1.PROD_PERM = tb3.PEID
    ) AS tb;

除此之外，Chris Lively巧妙地在注释中指出外部SELECT完全是多余的。以下是完全等同于第一个。

That aside, as Chris Lively cleverly points out in a comment the outer SELECT is totally superfluous. The following is totally equivalent to the first.

        SELECT tb1.PEID,tb2.col1,tb2.col2,tb3.col3 --, and so on
        FROM vCodesWithPEs as tb1 INNER JOIN vDeriveAvailabilityFromPE as tb2
        ON tb1.PROD_PERM = tb2.PEID 
        INNER JOIN PE_PDP tb3 ON tb1.PROD_PERM = tb3.PEID

或甚至

        SELECT * 
        FROM vCodesWithPEs as tb1 INNER JOIN vDeriveAvailabilityFromPE as tb2
        ON tb1.PROD_PERM = tb2.PEID 
        INNER JOIN PE_PDP tb3 ON tb1.PROD_PERM = tb3.PEID

但请避免尽可能使用SELECT * 。它可以在您执行交互式查询以保存输入时工作，但在生产代码中不会使用它。

but please avoid using SELECT * whenever possible. It may work while you are doing interactive queries to save typing, but in production code never use it.

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