SQL Server:如何按子串分组

Question

我有以下存储过程来从表中获取数据.该表有一个"区域"列,其中包含"APAC:China"等值,我正在使用子字符串函数来删除:以及后面的所有内容.

以下工作除了它分别列出所有记录而不是通过我的子串分组.所以我有几个区域为"APAC"的项目,而不是只有一个项目,所有项目都出现在下面.

我的存储过程:

CREATE PROCEDURE [dbo].[CountRegions]
AS
BEGIN
    SET NOCOUNT ON;
    SELECT      SUBSTRING(region, 1, CHARINDEX(':', region) - 1) AS region,
                COUNT(*) AS groupCount,
    FROM        SOPR_LogRequests
    WHERE       logStatus = 'active'
    GROUP BY    region
    ORDER BY    groupCount desc, region
    FOR XML PATH('regions'), ELEMENTS, TYPE, ROOT('ranks')
END

我的结果:

<ranks>
  <regions>
    <region>APAC</region>
    <groupCount>1</groupCount>
  </regions>
  <regions>
    <region>EMEA</region>
    <groupCount>1</groupCount>
  </regions>
  <regions>
    <region>APAC</region>
    <groupCount>1</groupCount>
  </regions>
  // ...
</ranks>

预期结果:

<ranks>
  <regions>
    <region>APAC</region>
    <groupCount>2</groupCount>
  </regions>
  <regions>
    <region>EMEA</region>
    <groupCount>1</groupCount>
  </regions>
  // ...
</ranks>

这里的任何人都可以帮我吗？

蒂姆,谢谢你的帮助.

Answer 1

你group by不知道你是在引用基础列,还是函数代码的输出(它会假设基础列),所以你需要重复代码group by:

CREATE PROCEDURE [dbo].[CountRegions]
AS
BEGIN
    SET NOCOUNT ON;
    SELECT      SUBSTRING(region, 1, CHARINDEX(':', region) - 1) AS region,
                COUNT(*) AS groupCount,
    FROM        SOPR_LogRequests
    WHERE       logStatus = 'active'
    GROUP BY    SUBSTRING(region, 1, CHARINDEX(':', region) - 1)
    ORDER BY    groupCount desc, region
    FOR XML PATH('regions'), ELEMENTS, TYPE, ROOT('ranks')
END