左外部連接3表

Question

我正在更新使用舊外部連接的舊建築的查詢（= *和* =）。我有3個表，我需要包括在一個外部聯接。

原來的查詢是：

SELECT s.SkillID , 
     NULL AS Signature , 
     NULL AS DPL , 
     CASE WHEN ISNULL(ds.DPL, dg.DPL) IS NULL 
      THEN p.ScaleTo - p.ScaleFrom + 1 
      ELSE ISNULL(ds.DPL, dg.DPL) 
     END AS DefaultDPL 
FROM tbJobs j , 
     tbSkills s 
     INNER JOIN tbSkillGroups sg ON s.SkillGroupID = sg.SkillGroupID , 
     tbPerfScales p , 
     tbDPLs ds , 
     tbDPLs dg 
WHERE j.JobID = 866 
     AND (ds.LevelID=*j.LevelID 
       AND ds.IDType = 1 
       AND ds.GroupOrSkillID=*s.SkillID 
      ) 
     AND (dg.LevelID=*j.LevelID 
       AND dg.IDType = 0 
       AND dg.GroupOrSkillID=*sg.SkillGroupID 
      ) 
     AND ((s.PerfScaleID IS NOT NULL 
       AND p.PerfScaleID = s.PerfScaleID 
      ) 
       OR (s.PerfScaleID IS NULL 
        AND p.PerfScaleID = sg.PerfScaleID 
       ) 
      ) 

我做：

SELECT s.SkillID , 
     NULL AS Signature , 
     NULL AS DPL , 
     CASE WHEN ISNULL(ds.DPL, dg.DPL) IS NULL 
      THEN p.ScaleTo - p.ScaleFrom + 1 
      ELSE ISNULL(ds.DPL, dg.DPL) 
     END AS DefaultDPL 
FROM tbPerfScales p , 
     tbSkills s 
     INNER JOIN tbSkillGroups sg ON s.SkillGroupID = sg.SkillGroupID , 
     tbJobs j 
     LEFT OUTER JOIN tbDPLs ds ON j.LevelID = ds.LevelID 
            AND s.SkillID = ds.GroupOrSkillID 
     LEFT OUTER JOIN tbDPLs dg ON j.LevelID = dg.LevelID 
            AND sg.SkillGroupID = dg.GroupOrSkillID 
WHERE j.JobID = 866 
     AND ds.IDType = 1 
     AND dg.IDType = 0 
     AND ((s.PerfScaleID IS NOT NULL 
       AND p.PerfScaleID = s.PerfScaleID 
      ) 
       OR (s.PerfScaleID IS NULL 
        AND p.PerfScaleID = sg.PerfScaleID 
       ) 
      ) 

出於某種原因，我得到的錯誤：

The multi-part identifier "s.SkillID" could not be bound.

我知道是在這部分：

tbJobs j 
    LEFT OUTER JOIN tbDPLs ds ON j.LevelID = ds.LevelID 
           AND s.SkillID = ds.GroupOrSkillID 

我不知道我在做什麼錯。

感謝任何幫助。 何塞

Answer 1

有聲明

INNER JOIN tbSkillGroups sg ON s.SkillGroupID = sg.SkillGroupID , 

後逗號這是因爲你之後有tbJobs，當它應該是其他表所示。我建議使用CROSS JOIN而不是在FROM子句中使用多個表，因爲它會更清晰。

下面是應該工作的查詢的基本重寫，儘管您應該能夠輕鬆地擺脫大部分交叉連接。

SELECT s.SkillID , 
     NULL AS Signature , 
     NULL AS DPL , 
     CASE WHEN ISNULL(ds.DPL, dg.DPL) IS NULL 
      THEN p.ScaleTo - p.ScaleFrom + 1 
      ELSE ISNULL(ds.DPL, dg.DPL) 
     END AS DefaultDPL 
FROM tbPerfScales p 
     CROSS JOIN tbSkills s 
     CROSS JOIN tbJobs j 
     INNER JOIN tbSkillGroups sg ON s.SkillGroupID = sg.SkillGroupID 
     LEFT OUTER JOIN tbDPLs ds ON j.LevelID = ds.LevelID 
            AND s.SkillID = ds.GroupOrSkillID 
     LEFT OUTER JOIN tbDPLs dg ON j.LevelID = dg.LevelID 
            AND sg.SkillGroupID = dg.GroupOrSkillID 
WHERE j.JobID = 866 
     AND ds.IDType = 1 
     AND dg.IDType = 0 
     AND ((s.PerfScaleID IS NOT NULL 
       AND p.PerfScaleID = s.PerfScaleID 
      ) 
       OR (s.PerfScaleID IS NULL 
        AND p.PerfScaleID = sg.PerfScaleID 
       ) 
      ) 

Answer 2

您不能混用不同的SQL語法。如果你打算使用ANSI-92，你需要糾正所有連接，而不僅僅是外部連接。一致性是關鍵。

現在，逗號是不正確的語法。你需要爲每個表添加一個連接，或者將每個表的連接拉出來，交給達倫的答案。 這是問題：

FROM tbPerfScales p , 
     tbSkills s 
     INNER JOIN tbSkillGroups sg ON s.SkillGroupID = sg.SkillGroupID , 
     tbJobs j 
     LEFT OUTER JOIN tbDPLs ds ON j.LevelID = ds.LevelID 
            AND s.SkillID = ds.GroupOrSkillID 
     LEFT OUTER JOIN tbDPLs dg ON j.LevelID = dg.LevelID 
            AND sg.SkillGroupID = dg.GroupOrSkillID 

它需要的線沿線：

FROM tbPerfScales p 
    INNER JOIN tbSkills s ON p.<field> = s.<field> 
     INNER JOIN tbSkillGroups sg ON s.SkillGroupID = sg.SkillGroupID 
     INNER JOIN tbJobs j on j.<field> = <table p? sg? not sure>.<field> 
     LEFT OUTER JOIN tbDPLs ds ON j.LevelID = ds.LevelID 
            AND s.SkillID = ds.GroupOrSkillID 
     LEFT OUTER JOIN tbDPLs dg ON j.LevelID = dg.LevelID 
            AND sg.SkillGroupID = dg.GroupOrSkillID