Question

我有一个查询，它读取代码的描述。两个查询都单独运行，它们返回一行但组合后又会产生一个重复的行。下面是查询

SELECT source, description = IsNull(Max(RTRIM(LTRIM(description))), 'UNKNOWN') 
  FROM SOURCES where source = RTRIM(LTRIM('SCDGIFT12')) 
 GROUP BY source

SELECT UPPER(SOURCECODE) as SOURCECODE,ISNULL(COUNT(ORDER_ID),0) AS ORDID 
  FROM SRC_CODE
 WHERE  CODE = 'SCDGIFT12' AND ORDER_DATE BETWEEN CONVERT(DATETIME,'10/01/2013')     
   AND  CONVERT(DATETIME,'01/26/2014') 
 GROUP BY sourcecode

SELECT SOURCECODE,ORDID,DESCRIPTION 
  FROM ( SELECT UPPER(SOURCECODE) as SOURCECODE, ISNULL(COUNT(ORDER_ID),0) AS ORDID )     
           FROM SRC_CODE  
          WHERE SOURCECODE = 'SCDGIFT12' and ORDER_DATE BETWEEN CONVERT(DATETIME,'10/01/2013') AND CONVERT(DATETIME,'01/26/2014')AND (UPPER(SOURCECODE) IS NOT NULL)  
          GROUP BY  UPPER(SOURCECODE)) AS T LEFT JOIN ( 
                SELECT source, description =  IsNull(Max(RTRIM(LTRIM(description))), 'UNKNOWN') from SOURCES group by source) as B ON  RTRIM(LTRIM(T.SOURCECODE)) = RTRIM(LTRIM(B.SOURCE))  
  ORDER BY sourcecode

Answer 1

我甚至不知道从哪里开始回答这个问题。

您的问题不正确，您没有加入两张桌子。您正在加入两个不同的结果集。
在前2个语句中，您只有两列，但在最后一个语句中，您有3列。
您的代码本身无效，在编译之前需要纠正几个语法错误。你的括号在错误的地方。
我甚至不确定你加入的是什么。
在加入和计数时，你应该把苹果和苹果和橙子放在一起，不要把它们分开计算，然后把它们放在一起，并期望它们都是一样的。

这是您重新格式化的代码，括号移到了正确的位置“我希望”

SELECT SOURCECODE
   ,ORDID
   ,DESCRIPTION
FROM ( SELECT UPPER(SOURCECODE) AS SOURCECODE
           ,ISNULL(COUNT(ORDER_ID), 0) AS ORDID
        FROM SRC_CODE
        WHERE SOURCECODE = 'SCDGIFT12'
            AND ORDER_DATE BETWEEN CONVERT(DATETIME, '10/01/2013')
                           AND     CONVERT(DATETIME, '01/26/2014')
            AND ( UPPER(SOURCECODE) IS NOT NULL )
        GROUP BY UPPER(SOURCECODE) ) AS T
LEFT JOIN ( SELECT source
                   ,description = ISNULL(MAX(RTRIM(LTRIM(description))), 'UNKNOWN')
                FROM SOURCES
                GROUP BY source ) AS B
    ON RTRIM(LTRIM(T.SOURCECODE)) = RTRIM(LTRIM(B.SOURCE))
ORDER BY sourcecode

我不确定你甚至想要用它来做什么，但如果你想要的是摆脱重复，你可以放DISTINCT来消除重复的行，但这并不能解决你的根本问题。你需要弄清楚你想要计算的是什么，并想出更好的方法将它放在一起而不是加入子查询。

连接2个表时重复行

1 个答案: