Question

使用SQL Server 2008 R2我目前有这个查询按预期工作。它返回一个简单的不同列表catalogID和catType。

注意 - catType字符串未在ALM_Catalog中进行规范化，因此内部选择

SELECT DISTINCT 
    catalogID, catType 
FROM 
    ALM_Catalog cat1 
WHERE 
    cat1.CatalogID = (SELECT max(CatalogID) 
                      FROM ALM_Catalog cat2 
                      WHERE cat1.catType = cat2.catType)
ORDER BY 
    catType;

我现在有一个ALM_CatalogAudience表。这是一个包含两列catalogID和businessGroupID的链接表。它旨在仅向某些业务组显示某些目录项。

所以我将上面的查询改为：

SELECT DISTINCT 
    cat1.catalogID, cat1.catType 
FROM 
    ALM_Catalog cat1
LEFT OUTER JOIN
    ALM_CatalogAudience ON cat1.catalogID = ALM_CatalogAudience.catalogID
WHERE 
    cat1.CatalogID = (SELECT MAX(CatalogID) 
                      FROM ALM_Catalog cat2 
                      WHERE cat1.catType = cat2.catType)
    AND ALM_CatalogAudience.businessGroupID = (SELECT  md_businessGroup.businessGroupID  
                                               FROM 
                                                  ((directory d  
                                               LEFT OUTER JOIN 
                                                  md_department ON d.departmentID =  md_department.departmentID)
                                               LEFT OUTER JOIN 
                                                  md_businessGroup ON md_department.businessGroupID = md_businessGroup.businessGroupID) 
                                               WHERE directoryID = 18230)
ORDER BY 
    cat1.catType;

什么都不返回，我看不出原因。注 - 第二个子选择（SELECT md_businessGroup ...）返回1，当我运行它时：

select * from ALM_CatalogAudience where businessGroupID=1

它返回132条记录。我错过了什么？提前谢谢。

编辑：一些示例输出是：

1362    Accessories & Parts
1368    Audio & Video
1399    Batteries & Power
1412    Cables & Connectors
1418    Carrying Cases
1424    Docks & Port Replicators
1429    Keyboards & Mice

编辑：看来这个位置：

cat1.CatalogID = (SELECT MAX(CatalogID) MAX

是我犯的错误。 MAX catalogID不一定映射到businessGroupID 1，除非目录项只被映射到一个恰好是1的业务组。所以我相信这对我现在有用：

SELECT DISTINCT  max(cat1.catalogID) , cat1.catType FROM ALM_Catalog cat1
left outer join ALM_CatalogAudience on cat1.catalogID = ALM_CatalogAudience.catalogID
WHERE 
 ALM_CatalogAudience.businessGroupID = ( 
    SELECT  md_businessGroup.businessGroupID  
    from directory d  
    LEFT OUTER JOIN md_department 
              on d.departmentID =  md_department.departmentID 
    LEFT OUTER JOIN md_businessGroup 
              on md_department.businessGroupID = md_businessGroup.businessGroupID 
    where directoryID=18230)
group BY cat1.catType
order BY cat1.catType;

Answer 1

SELECT DISTINCT cat1.catalogID, cat1.catType 
  FROM ALM_Catalog cat1
 left outer join ALM_CatalogAudience 
   on cat1.catalogID = ALM_CatalogAudience.catalogID
WHERE 
   cat1.CatalogID=
        (SELECT max(CatalogID) from ALM_Catalog cat2 WHERE cat1.catType=cat2.catType)
   AND ALM_CatalogAudience.businessGroupID = 
      (
          SELECT  md_businessGroup.businessGroupID  
            from directory d  
         LEFT OUTER JOIN md_department 
                      on d.departmentID =  md_department.departmentID 
         LEFT OUTER JOIN md_businessGroup 
                      on md_department.businessGroupID = md_businessGroup.businessGroupID 
         where directoryID=18230
      )
  ORDER BY cat1.catType;

我很惊讶您没有收到语法错误。我刚修好它并没有改变任何东西，如果它仍然无法工作，那么我们需要一些样本数据。

好的，因为仍然没有记录我能告诉你的是检查问题所在的方法。

运行：

 SELECT  md_businessGroup.businessGroupID  
        from directory d  
     LEFT OUTER JOIN md_department 
                  on d.departmentID =  md_department.departmentID 
     LEFT OUTER JOIN md_businessGroup 
                  on md_department.businessGroupID = md_businessGroup.businessGroupID 
     where directoryID=18230

如果你把号码写下来了。如果你在这里得到0记录，你应该检查目录表并再次测试脚本。

2.再次检查ALM_CatalogAudience并保存结果

select * from ALM_CatalogAudience where businessGroupID = the number you just get;

如果不是，则ALM_CatalogAudience不具有该groupID。如果获取记录，请将其保存在临时表中。

左连接ALM_Catalog和临时表。我想你现在可以得到它

Answer 2

您可能希望修复原始查询以匹配Raffaello.D.Huke为您修复的版本。如果您的子查询和ALM_CatalogAudience.businessGroupID都返回1，则可能是您的businessGroupID不是同一类型。你可以试试下面的吗？

...
AND CAST(ALM_CatalogAudience.businessGroupID AS VARCHAR) = 
  (
      SELECT  CAST(md_businessGroup.businessGroupID AS VARCHAR) 
        from directory d  
...

T-SQL：选择使用子选择不返回任何内容

2 个答案: