下面的代码将适用于Sql Server 2000/2005/2008

CREATE FUNCTION fnConcatVehicleCities(@VehicleId SMALLINT)
RETURNS VARCHAR(1000) AS
BEGIN
  DECLARE @csvCities VARCHAR(1000)
  SELECT @csvCities = COALESCE(@csvCities + ', ', '') + COALESCE(City,'')
  FROM Vehicles 
  WHERE VehicleId = @VehicleId 
  return @csvCities
END

-- //Once the User defined function is created then run the below sql

SELECT VehicleID
     , dbo.fnConcatVehicleCities(VehicleId) AS Locations
FROM Vehicles
GROUP BY VehicleID

如果你使用的是SQL Server 2005，你可以使用FOR XML PATH命令。

SELECT [VehicleID]
     , [Name]
     , (STUFF((SELECT CAST(', ' + [City] AS VARCHAR(MAX)) 
         FROM [Location] 
         WHERE (VehicleID = Vehicle.VehicleID) 
         FOR XML PATH ('')), 1, 2, '')) AS Locations
FROM [Vehicle]

这比使用光标容易得多，而且似乎工作得相当好。

更新

对于那些在新版本的SQL Server中仍然使用这种方法的人来说，还有另一种方法，它更简单，性能更好 自SQL Server 2017以来已经可用的STRING_AGG方法。

SELECT  [VehicleID]
       ,[Name]
       ,(SELECT STRING_AGG([City], ', ')
         FROM [Location]
         WHERE VehicleID = V.VehicleID) AS Locations
FROM   [Vehicle] V

这还允许将不同的分隔符指定为第二个参数，比前一种方法提供了更多的灵活性。

注意，Matt的代码将导致在字符串的末尾增加一个逗号;使用COALESCE(或ISNULL)，如Lance的链接中所示，使用了类似的方法，但没有给你留下一个额外的逗号。为了完整起见，下面是兰斯在sqlteam.com上的相关代码:

DECLARE @EmployeeList varchar(100)
SELECT @EmployeeList = COALESCE(@EmployeeList + ', ', '') + 
    CAST(EmpUniqueID AS varchar(5))
FROM SalesCallsEmployees
WHERE SalCal_UniqueID = 1

对于其他答案，阅读答案的人必须知道车辆表，并创建车辆表和数据来测试解决方案。

下面是一个使用SQL Server“Information_Schema”的例子。表列”。通过使用该解决方案，不需要创建表或添加数据。这个示例为数据库中的所有表创建一个以逗号分隔的列名列表。

SELECT
    Table_Name
    ,STUFF((
        SELECT ',' + Column_Name
        FROM INFORMATION_SCHEMA.Columns Columns
        WHERE Tables.Table_Name = Columns.Table_Name
        ORDER BY Column_Name
        FOR XML PATH ('')), 1, 1, ''
    )Columns
FROM INFORMATION_SCHEMA.Columns Tables
GROUP BY TABLE_NAME 

在单个SQL查询中，不使用FOR XML子句。 公共表表达式用于递归地连接结果。

-- rank locations by incrementing lexicographical order
WITH RankedLocations AS (
  SELECT
    VehicleID,
    City,
    ROW_NUMBER() OVER (
        PARTITION BY VehicleID 
        ORDER BY City
    ) Rank
  FROM
    Locations
),
-- concatenate locations using a recursive query
-- (Common Table Expression)
Concatenations AS (
  -- for each vehicle, select the first location
  SELECT
    VehicleID,
    CONVERT(nvarchar(MAX), City) Cities,
    Rank
  FROM
    RankedLocations
  WHERE
    Rank = 1

  -- then incrementally concatenate with the next location
  -- this will return intermediate concatenations that will be 
  -- filtered out later on
  UNION ALL

  SELECT
    c.VehicleID,
    (c.Cities + ', ' + l.City) Cities,
    l.Rank
  FROM
    Concatenations c -- this is a recursion!
    INNER JOIN RankedLocations l ON
        l.VehicleID = c.VehicleID 
        AND l.Rank = c.Rank + 1
),
-- rank concatenation results by decrementing length 
-- (rank 1 will always be for the longest concatenation)
RankedConcatenations AS (
  SELECT
    VehicleID,
    Cities,
    ROW_NUMBER() OVER (
        PARTITION BY VehicleID 
        ORDER BY Rank DESC
    ) Rank
  FROM 
    Concatenations
)
-- main query
SELECT
  v.VehicleID,
  v.Name,
  c.Cities
FROM
  Vehicles v
  INNER JOIN RankedConcatenations c ON 
    c.VehicleID = v.VehicleID 
    AND c.Rank = 1

从我所看到的FOR XML(如前所述)是唯一的方法，如果你还想选择其他列(我猜大多数会)，就像OP所做的那样。 使用合并(@var……不允许包含其他列。

更新: 感谢programmingsolutions.net，有一种方法可以删除“尾随”逗号。 通过使它成为一个前导逗号，并使用MSSQL的STUFF函数，你可以将第一个字符(前导逗号)替换为一个空字符串，如下所示:

stuff(
    (select ',' + Column 
     from Table
         inner where inner.Id = outer.Id 
     for xml path('')
), 1,1,'') as Values