LEFT OUTER JOIN 3表

Question

我正在更新使用旧结构进行外连接的查询(=*和*=).我有3个表,我需要包含在外连接中.

原始查询是:

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
                 )
            )

我正在做:

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
                 )
            )

出于某种原因,我收到了错误:

无法绑定多部分标识符"s.SkillID".

我知道就是这部分:

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

我不确定我做错了什么.

谢谢你的帮助.何塞

Answer 1

声明后有一个逗号

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

这是因为你之后有tbJobs,它应该在其他表中.我建议使用CROSS JOIN而不是在FROM子句中只有多个表,因为它会更清楚.

这是您的查询的基本重写,应该可以工作,但您应该能够轻松摆脱大多数交叉连接.

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
                 )
            )