SQL双外连接？

Question

我有以下表格：

Users - Users of the site 
Matchups - Matchups between two teams 
Periods - The periods in which matchups take place 
MatchupResults - The results of the matchups 
UserPicks - The user's choice of who will win the matchup (5 picks for each period) 
Teams - Teams in the matchups 

的关系如下：

Matchups.HomeID/Matchups.VisitorID = Teams.ID 
Matchups.PeriodID = Periods.ID 
MatchupResults.MatchupID = Matchups.ID 
UserPicks.MatchupID = Matchups.ID 
UserPicks.UserID = User.ID 

我想获得（英文）是：

所有用户，无论他们是否无论他们是否有成绩，都做出了挑战和所有对决。如果他们有结果或选择，我希望他们显示。

我已经得到这个查询来获取我的对决，因为我希望他们：

select P.ID as PeriodID, 
     M.ID as MatchupID, 
     V.ID as VisitorTeam, 
     H.ID as HomeTeam, 
     MR.VisitorScore, 
     MR.HomeScore, 
     CASE WHEN (M.PointSpread <= 0) THEN 
        CASE WHEN (MR.HomeScore + M.PointSpread > MR.VisitorScore) THEN H.ID ELSE V.ID END 
      WHEN (M.PointSpread > 0) THEN 
        CASE WHEN (MR.HomeScore + M.PointSpread < MR.VisitorScore) THEN V.ID ELSE H.ID END 
      ELSE NULL 
     END AS TeamThatCoveredSpread 
from Matchups M 
left outer join MatchupResults MR ON MR.MatchupID = M.ID 
inner join Teams V ON V.ID = M.VisitorID 
inner join Teams H ON H.ID = M.HomeID 
inner join Periods P ON P.ID = M.PeriodID 

但是我有包括用户和他们的选秀权的麻烦 - 不管我尝试它让我的过滤结果只有用户选择的游戏。

因此，如果有10用户我选择1对决，我应该看到所有10个用户以及一个TeamID作为自己挑选或NULL这意味着他们没有做一挑的那场比赛。

更新：对于上面的查询的样本结果与简单指定期限1：

Answer 1

我回答我的问题，感谢您的建议，并标明了每个答案和征求意见你的时间。

谢谢您的宝贵时间，这里就是答案和结果集为一个周期/用户（仅适用于简单过滤这里）：

insert #UserMatchups 
select U.ID, 
     M.ID, 
     M.VisitorID, 
     M.HomeID, 
     M.HomeSpread 
from Users U, Matchups M 
where PeriodID = @PeriodID 

select M.UserID, 
     M.MatchupID, 
     CASE WHEN (M.Spread <= 0) THEN 
        CASE WHEN (MR.HomeScore + M.Spread > MR.VisitorScore) THEN M.HomeID ELSE M.VisitorID END 
      WHEN (M.Spread > 0) THEN 
        CASE WHEN (MR.HomeScore + M.Spread < MR.VisitorScore) THEN M.VisitorID ELSE M.HomeID END 
      ELSE NULL 
     END AS TeamThatCoveredSpread, 
     UP.TeamID AS UserPick 
from #UserMatchups M 
left outer join MatchupResults MR ON MR.MatchupID = M.MatchupID 
left outer join UserPicks UP ON UP.UserID = M.UserID and UP.MatchupID = M.MatchupID 
where M.UserID = 1 

Answer 2

这里的问题是，你有INNER JOIN S的取决于比赛的LEFT OUTER JOIN如此，当然，如果有没有你的LEFT OUTER JOIN的结果，那么INNER JOIN无法返回结果。
你需要消除你INNER JOIN因为他们需要在MatchupResults

数据使他们每个人的LEFT OUTER JOIN然后把他们JOIN条件是这样的WHERE子句中....

WHERE 
    (M.[VisitorID] IS NULL OR V.[ID] = M.[VisitorID]) 
    AND (M.[HomeID] IS NULL OR H.[ID] = M.[HomeID]) 
    AND (M.[PeriodID] IS NULL OR P.ID = M.[PeriodID]) 

所以，现在你JOIN将继续，但只有当MatchupResults是JOIN ed

Answer 3

我认为你应该从用户开始，然后左加入。如果你真的想要INNER JOIN，你可以这样做，但你需要把它放在Paranes内。在JOIN CLAUSE中加入@Matchupid也可能是一个好主意，因为这样你不必担心拿起其他比赛。

这应该工作（分析，但未经测试）

SELECT 
    P.ID as PeriodID, 
    M.ID as MatchupID, 
    V.ID as VisitorTeam, 
    H.ID as HomeTeam, 
    MR.VisitorScore, 
    MR.HomeScore, 
    CASE WHEN (M.PointSpread <= 0) THEN 
       CASE WHEN (MR.HomeScore + M.PointSpread > MR.VisitorScore) THEN H.ID ELSE V.ID END 
     WHEN (M.PointSpread > 0) THEN 
       CASE WHEN (MR.HomeScore + M.PointSpread < MR.VisitorScore) THEN V.ID ELSE H.ID END 
     ELSE NULL 
    END AS TeamThatCoveredSpread 
FROM users u 
     LEFT JOIN userpicks up 
     ON u.id = up.user_id 
     LEFT JOIN matchups m 
     ON up.matchupid = m.id 
      AND up.matchupid = @Matchupid 
     LEFT OUTER JOIN (matchupresults mr 
         INNER JOIN teams v 
          ON v.id = m.visitorid 
         INNER JOIN teams h 
          ON h.id = m.homeid 
         INNER JOIN periods p 
          ON p.id = m.periodid) 
     ON mr.matchupid = m.id 

Answer 4

这个怎么样：

;WITH matchups (periodid, matchupid, vistortteam,HomeTeam,VisitorScore, HomeScore) 
(
SELECT P.ID AS PeriodID 
, M.ID AS MatchupID 
, V.ID AS VisitorTeam 
, H.ID AS HomeTeam 
, MR.VisitorScore 
, MR.HomeScore 
,CASE WHEN (M.PointSpread <= 0) 
     THEN 
        CASE WHEN (MR.HomeScore + M.PointSpread > MR.VisitorScore) 
         THEN H.ID 
        ELSE V.ID END     
     WHEN (M.PointSpread > 0) 
     THEN 
      CASE WHEN (MR.HomeScore + M.PointSpread < MR.VisitorScore) 
       THEN V.ID 
      ELSE H.ID END    
     ELSE NULL   
     END AS TeamThatCoveredSpread 
FROM Matchups M 
LEFT OUTER JOIN MatchupResults MR ON MR.MatchupID = M.ID 
INNER JOIN Teams V ON V.ID = M.VisitorID 
INNER JOIN Teams H ON H.ID = M.HomeID 
INNER JOIN Periods P ON P.ID = M.PeriodID 
) 

SELECT * 
FROM USERS u 
JOIN USERPIcks up ON u.id = up.userid 
LEFT JOIN matchups m ON m.MatchupID = up.MatchupID