数据合并，汇总.......
表1：DocWait
ID(增)     DocID           SendID         WaitUserID     NodeID      
1 114               1 1 1
2 114     2 2 2
3 114               1 2 2
4 114               5 2 3
5 114     2 3 1
6 115               3                           2 1


表2：DocSend
SendID(增)       SendUserID       SendDate        
1                         1                         2005-4-5
2                         2               2006-5-7
3                         5                   2007-7-7


表3：UserDef
UserID(增)     Name
1         用户1
2                       用户2  
3         用户3
....
5         用户5

问题：表1，SendID     -> 表2：SendID
表2，SendUserID     -> 表3：UserID
当
当前用户WaitUserID=2时显示,相同DOCID，NodeID合并
得到以下结果:
ID             DocID           SendID                 WaitUserID
1 114               用户2,用户1 2005-4-5
4 114               用户5 2005-4-5
2 115     用户3 2007-7-7

------解决方案--------------------
CREATE TABLE DocWait
(
ID INT IDENTITY(1,1),
DocID INT,
SendID INT,
WaitUserID INT,
NodeID INT
)
INSERT INTO DocWait(DocID,SendID,WaitUserID,NodeID)
SELECT 114,1,1,1 UNION ALL
SELECT 114,2,2,2 UNION ALL
SELECT 114,1,2,2 UNION ALL
SELECT 114,5,2,3 UNION ALL
SELECT 114,2,3,1 UNION ALL
SELECT 115,3,2,1
CREATE TABLE DocSend
(
SendID INT IDENTITY(1,1),
SendUserID INT,
SendDate DATETIME
)
INSERT INTO DocSend(SendUserID,SendDate)
SELECT 1, '2005-4-5 ' UNION ALL
SELECT 2, '2006-5-7 ' UNION ALL
SELECT 5, '2007-7-7 '
CREATE TABLE UserDef
(
UserID INT IDENTITY(1,1),
Name VARCHAR(20)
)
INSERT INTO UserDef (Name)
SELECT '用户1 ' UNION ALL
SELECT '用户2 ' UNION ALL
SELECT '用户3 ' UNION ALL
SELECT '用户4 ' UNION ALL
SELECT '用户5 '


CREATE FUNCTION dbo.f_strjoin(@DocID INT,@NodeID INT)
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re= ' '
SELECT @re=@re+ ', '+CAST(A.Name as varchar)
FROM UserDef A INNER JOIN DocSend B ON B.SendUserID=A.UserID
INNER JOIN DocWait C ON B.SendID=C.SendID
WHERE C.DocID=@DocID AND C.NodeID=@NodeID
RETURN(STUFF(@re,1,1, ' '))
END

SELECT A.ID,A.DocID,dbo.f_strjoin(A.DocID,A.NodeID) SendID,B.SendDate WaitUserID FROM DocWa