1

我自己无法弄清楚这一点。希望有人可以帮助我。

我有三个表：users、cards和refereesusers_cards

用户：

id  |   userName  |   referee_id
----------------------------
1   |   u1        |    1
2   |   u2        |    1
3   |   u3        |    2

裁判员：

id  |   refName
--------------
1   |   ref1
2   |   ref2

牌：

id  |   cardName
--------------
1   |   card1
2   |   card2

用户卡：

user_id  |   card_id  |   color   |   number
-------------------------------------------
1        |   1        |   red     |   123
1        |   2        |   yellow  |   312
2        |   2        |   yellow  |   523
3        |   1        |   red     |   344

我想要得到的结果是：

id   |   userName   |   refName   |   cards
1    |      u1      |    ref1     |   card1: red (123), card2: yellow (312)
2    |      u2      |    ref1     |   card2: yellow (523)
3    |      u3      |    ref2     |   card1: red (344)

等等...

当用户拥有不止一张卡时，我所能得到的只是多行。那么我怎样才能像这样组合它们。

感谢任何可以帮助我的人！

编辑：

目前我只是使用LEFT JOINs

SELECT UserName, refName cardName, color, number,
FROM users
LEFT JOIN referees ON users.referee_id = referees.id
LEFT JOIN users_cards ON users.id = users_cards.user_id
LEFT JOIN cards ON dbo.users_cards.card_id = cards.id
4

2 回答 2

0

我认为没有简单的方法来格式化表格的结果并将其附加到您的结果中。您可以尝试使用以下内容执行存储过程：

CREATE TABLE #temp
(
    user_id int,
    CardString nvarchar(50)
)

CREATE TABLE #userCards
(
    user_id int,
    CardsList nvarchar(50)
)

DECLARE @UserID int,
        @cardName nvarchar(50),
        @cardList nvarchar(250) 

INSERT INTO #temp
SELECT user_id, cardName + ': ' + color + ' (' + number + ')'
FROM User_Cards AS UC
INNER JOIN Cards AS C ON C.card_id = UC.card_id

WHILE EXISTS (SELECT * FROM #temp)
BEGIN
   SELECT TOP(1) @UserID = user_id FROM #temp

   SET @cardList = ''

   WHILE EXISTS (SELECT * FROM #temp WHERE user_id = @UserID)
   BEGIN
      SELECT TOP(1) @cardName = [CardString] FROM #temp WHERE user_id = @UserID
      IF @cardList <> ''
         SET @cardList = @cardList + ', '
      SET @cardList = @cardList + @cardName
   END

   INSERT INTO #userCards
   VALUES (user_id, @cardList)
END

SELECT users.id, users.userName, referees.refName, CardsList 
FROM users
LEFT JOIN referees ON users.referee_id = referees.id
LEFT JOIN #userCards ON #userCards.card_id = users.user_id

DROP TABLE #userCards
DROP TABLE #temp

这将返回您想要的内容。您还可以定义一个聚合函数（参见http://msdn.microsoft.com/en-us/library/ms190678.aspx）

于 2013-07-18T10:10:03.320 回答
0 
SELECT users.id, UserName, refName,
 cards = (
    SELECT  
      STUFF(( 
           SELECT ', card' + CAST(ROW_NUMBER() OVER (ORDER BY cards.id) AS VARCHAR) 
                  +': '+ color + '(' + CAST(number AS VARCHAR) +')'
           FROM 
              users_cards
              LEFT JOIN cards ON dbo.users_cards.card_id = cards.id
           WHERE users.id = users_cards.user_id
           FOR XML PATH('')), 1, 1, '') 
  )
FROM users
LEFT JOIN referees ON users.refereeid = referees.id
于 2013-07-18T10:12:28.990 回答