SQL Server相当于WM_CONCAT函数

Question

可能重复:
SQL Server中的Concat字段值为字符串

什么是SQL Server等效的WM_CONCAT？

Answer 1

你没有相应的功能,但你仍然可以模拟(使用CROSS APPLY和FOR XML PATH('')).例,

USERID  ADDRESSLINE1
==========================
1       First Street
1       Second Street
2       32th Street
2       24th Street
2       25th Street

将导致

USERID  ADDRESSLIST
============================
1       First Street, Second Street
2       32th Street, 24th Street, 25th Street

使用此查询:

SELECT  a.UserID, 
        SUBSTRING(d.Addresses,1, LEN(d.Addresses) - 1) AddressList
FROM
        (
            SELECT DISTINCT UserID
            FROM tableName
        ) a
        CROSS APPLY
        (
            SELECT [AddressLine1] + ', ' 
            FROM tableName AS B 
            WHERE A.UserID = B.UserID 
            FOR XML PATH('')
        ) D (Addresses) 

SQLFiddle演示