Question

我正在使用SQL Server 2008，我需要创建一个列的常见分隔列表。我知道怎么做，但是我需要这个时间，而我使用分析函数，我的意思是我不想使用group by子句。由于我还将在外部查询“ where row_num = 1 ”

中选择记录

以下是查询：

SELECT UserId
      ,ProductList
      ,Value
  FROM
  (
SELECT p.UserId 
     ,p.Value
     , ROW_NUMBER()OVER (PARTITION BY p.UserId ORDER BY p.RecordCreateDate asc) AS 'row_num'
     --here I need a solution  OVER (PARTITION BY p.UserId) AS 'ProductList'
  FROM Products p
       INNER JOIN
       Users u
       ON p.UserId = u.Id
       ) result
 WHERE result.row_num = 1

用户数据：

Id       Name      ....
 1       John
 2       Anton
 3       Craig

产品数据：

Id      UserId      Name     RecordCreateDate   Value
 1           1         a           21.12.2012      10
 2           1         b           11.12.2012      20
 3           1         c           01.12.2012      30
 4           2         e           05.12.2012      40
 5           2         f           17.12.2012      50
 6           3         d           21.12.2012      60 
 7           3         i           31.12.2012      70

我需要一个结果，例如：

UserId     ProductList      Value
     1           a,b,c         30
     2             e,f         40
     3             d,i         60

感谢您的帮助

Answer 1

由于您要对row_num = 1进行过滤，因此您需要将查询放入CTE或其他包含产品额外列的内容中。然后，您可以使用for XML路径技巧在外部查询中构建逗号分隔的字符串，而不使用group by。

;WITH C as
(
  SELECT p.UserId 
       , ROW_NUMBER()OVER (PARTITION BY p.UserId ORDER BY p.RecordCreateDate asc) AS 'row_num'
       --, Some other fields from Products
    FROM Products p
         INNER JOIN
         Users u
         ON p.UserId = u.Id
)
SELECT UserId,
       --, Some other fields from Products
       --, Build the concatenated list here using for xml path()
FROM C
WHERE C.row_num = 1

Answer 2

我不确定你在开头会问什么，但这会给你所要求的输出

SELECT UserId,
  STUFF((SELECT ',' + ProductName from Products p WHERE p.UserID = u.UserID FOR XML PATH('')), 1, 1, '') as ProductList
FROM Users u

Answer 3

只是为了完整。删除实际解决方案的＃符号。

SET NOCOUNT ON;

CREATE TABLE #users
(
    Id INT,
    Name VARCHAR(32)
);

INSERT #users VALUES
(1,'John'),
(2,'Anton'),
(3,'Craig');

CREATE TABLE #products
(
    Id INT,
    UserId INT,
    Name VARCHAR(32),
    RecordCreateDate DATE,
    Value INT
);

INSERT #products VALUES
(1,1,'a','2012-12-21',10),
(2,1,'b','2012-12-11',20),
(3,1,'c','2012-12-01',30),
(4,2,'e','2012-12-05',40),
(5,2,'f','2012-12-17',50),
(6,3,'d','2012-12-21',60), 
(7,3,'i','2012-12-31',70);

查询：

;WITH x AS 
(
    SELECT UserId, Value, 
        row_num = ROW_NUMBER() OVER 
        (
              PARTITION BY UserId 
              ORDER BY RecordCreateDate
        )
        FROM #products
)
SELECT
  x.UserId,
  u.Name,
  ProductList = STUFF((
     SELECT ',' + Name
        FROM #Products AS p 
        WHERE p.UserId = x.UserId 
        FOR XML PATH(''), TYPE).value('.', 'varchar(max)'),1,1,''),
  x.Value
FROM x
INNER JOIN #users AS u
ON x.UserId = u.Id
WHERE x.row_num = 1;

然后清理：

DROP TABLE #users, #products;

结果：

UserId  Name    ProductList  Value
1       John    a,b,c        30
2       Anton   e,f          40
3       Craig   d,i          60

sql逗号分隔分析函数中列的列表

3 个答案: