sql - 使用 COALESCE 合并多行

Question

使用 SQL-Server 2012

我有下表:

Id      Description 
6192    Salzburg
6193    Salzburg
6194    Salzburg
6196    Innsbruck
6197    Innsbruck
6198    Innsbruck
6199    Innsbruck
6201    Bregenz
6202    Bregenz
6203    Bregenz

我想选择每个不同的“描述”，并将所有 ID 放在一个字符串中:

    Description     Ids
    Salzburg        '6192,6193,6194'
    Innsbruck       '6196,6197,6198'

我在这个网站上看到了一些类似的代码[ How to concatenate text from multiple rows into a single text string in SQL server? ，但我还无法弄清楚我的目的(不想使用 XML 路径!)。这是我到目前为止所尝试过的:

DECLARE @ids AS Nvarchar(MAX)
SELECT  @ids = COALESCE(@ids + ',', '') + CAST(t.Id AS nvarchar(5))
    FROM (SELECT tmp.Id FROM (SELECT id, [Description] FROM tblMasterPropValues WHERE IdCategory = 253 AND IsActive = 1) as tmp
        WHERE [Description] = tmp.[Description]) AS t
SELECT @ids
--SELECT DISTINCT [Description], @ids AS IDs FROM tblMasterPropValues WHERE IdCategory = 253 AND IsActive = 1 AND Id IN (@ids)

我实在无法理解这个问题，希望得到任何帮助。

Answer 1

您可以尝试使用STUFF()函数

SELECT description,  Ids = STUFF(
             (SELECT ',' + Id
              FROM tblMasterPropValues t1
              WHERE t1.description = t2.description
              FOR XML PATH (''))
             , 1, 1, '') from tblMasterPropValues t2
group by description;