Oracle和左外部連接

Question

我對這個Hibernate生成的Oracle Sql感到困惑。數據庫中有一個用戶，但他們沒有任何徽章，但我正在對所有內容進行左外連接。所以用戶應該每次回來，不管他們有沒有徽章。如果我刪除這些行，則會將用戶拉回。不管離開外部連接是否設想將某人帶回來？

AND b4_.ACTIVE=1 
     AND B4_.STATUS='A' 
     AND UB2_.VISIBLE=1 
     and bl3_.ACTIVE=1 

休眠的Sql然在SQL Developer中

select 
      this_.ID as ID0_11_, 
      this_.BIOGRAPHY as BIOGRAPHY0_11_, 
      this_.DATECREATED as DATECREA3_0_11_, 
      this_.EMAIL as EMAIL0_11_, 
      this_.ENABLED as ENABLED0_11_, 
      this_.FIRSTNAME as FIRSTNAME0_11_, 
      this_.HIDECONNECTORS as HIDECONN7_0_11_, 
      this_.HIDEEMAIL as HIDEEMAIL0_11_, 
      this_.HIDENAME as HIDENAME0_11_, 
      this_.LASTNAME as LASTNAME0_11_, 
      this_.PASSWORD as PASSWORD0_11_, 
      this_.SALT as SALT0_11_, 
      this_.TITLE as TITLE0_11_, 
      this_.USERNAME as USERNAME0_11_, 
      this_.WARNINGS as WARNINGS0_11_, 
      (SELECT 
       COUNT(*) 
      FROM 
       Followers f 
      WHERE 
       f.followerid = this_.Id) as formula0_11_, 
      assets6_.USERID as USERID13_, 
      asset7_.ID as ASSETID13_, 
      asset7_.ID as ID2_0_, 
      asset7_.ACTIVE as ACTIVE2_0_, 
      asset7_.DATECREATED as DATECREA3_2_0_, 
      asset7_.DATEMODIFIED as DATEMODI4_2_0_, 
      asset7_.DESCRIPTION as DESCRIPT5_2_0_, 
      asset7_.FILENAME as FILENAME2_0_, 
      asset7_.FILEPATH as FILEPATH2_0_, 
      asset7_.TITLE as TITLE2_0_, 
      asset7_.TYPE as TYPE2_0_, 
      roles8_.USERID as USERID14_, 
      role9_.ID as ROLEID14_, 
      role9_.ID as ID1_1_, 
      role9_.DISPLAYNAME as DISPLAYN2_1_1_, 
      role9_.NAME as NAME1_1_, 
      ub2_.USERID as USERID15_, 
      ub2_.ID as ID15_, 
      ub2_.ID as ID12_2_, 
      ub2_.BADGELEVELID as BADGELEV5_12_2_, 
      ub2_.DATECREATED as DATECREA2_12_2_, 
      ub2_.ISMANUAL as ISMANUAL12_2_, 
      ub2_.USERID as USERID12_2_, 
      ub2_.VISIBLE as VISIBLE12_2_, 
      bl3_.ID as ID9_3_, 
      bl3_.ACTIVE as ACTIVE9_3_, 
      bl3_.ASSETID as ASSETID9_3_, 
      bl3_.BADGEID as BADGEID9_3_, 
      bl3_.DATECREATED as DATECREA3_9_3_, 
      bl3_.DATEMODIFIED as DATEMODI4_9_3_, 
      bl3_.DESCRIPTION as DESCRIPT5_9_3_, 
      bl3_.FILTERS as FILTERS9_3_, 
      bl3_."ORDER" as ORDER7_9_3_, 
      (SELECT 
       COUNT(*) 
      FROM 
       USERBADGES ub 
      WHERE 
       ub.badgeLevelId = bl3_.Id) as formula1_3_, 
      (bl3_."ORDER" - 1) as formula2_3_, 
      asset12_.ID as ID2_4_, 
      asset12_.ACTIVE as ACTIVE2_4_, 
      asset12_.DATECREATED as DATECREA3_2_4_, 
      asset12_.DATEMODIFIED as DATEMODI4_2_4_, 
      asset12_.DESCRIPTION as DESCRIPT5_2_4_, 
      asset12_.FILENAME as FILENAME2_4_, 
      asset12_.FILEPATH as FILEPATH2_4_, 
      asset12_.TITLE as TITLE2_4_, 
      asset12_.TYPE as TYPE2_4_, 
      b4_.ID as ID10_5_, 
      b4_.ACTIVE as ACTIVE10_5_, 
      b4_.DATECREATED as DATECREA3_10_5_, 
      b4_.DATEMODIFIED as DATEMODI4_10_5_, 
      b4_.DESCRIPTION as DESCRIPT5_10_5_, 
      b4_.ENDDATE as ENDDATE10_5_, 
      b4_.NAME as NAME10_5_, 
      b4_.PUBLISHDETAILS as PUBLISHD8_10_5_, 
      b4_.STARTDATE as STARTDATE10_5_, 
      b4_.STATUS as STATUS10_5_, 
      b4_.UPDATEOWNERID as UPDATEO11_10_5_, 
      b4_.OWNERID as OWNERID10_5_, 
      (SELECT 
       COUNT(*) 
      FROM 
       BadgeLevels bl 
      WHERE 
       bl.badgeId = b4_.Id) as formula3_5_, 
      (CASE 
       WHEN (SELECT 
        COUNT(*) 
       FROM 
        BadgeLevels bl 
       WHERE 
        bl.badgeId = b4_.Id) > 1 THEN 'Ladder' 
       ELSE 'Single' 
      END) as formula4_5_, 
      user14_.ID as ID0_6_, 
      user14_.BIOGRAPHY as BIOGRAPHY0_6_, 
      user14_.DATECREATED as DATECREA3_0_6_, 
      user14_.EMAIL as EMAIL0_6_, 
      user14_.ENABLED as ENABLED0_6_, 
      user14_.FIRSTNAME as FIRSTNAME0_6_, 
      user14_.HIDECONNECTORS as HIDECONN7_0_6_, 
      user14_.HIDEEMAIL as HIDEEMAIL0_6_, 
      user14_.HIDENAME as HIDENAME0_6_, 
      user14_.LASTNAME as LASTNAME0_6_, 
      user14_.PASSWORD as PASSWORD0_6_, 
      user14_.SALT as SALT0_6_, 
      user14_.TITLE as TITLE0_6_, 
      user14_.USERNAME as USERNAME0_6_, 
      user14_.WARNINGS as WARNINGS0_6_, 
      (SELECT 
       COUNT(*) 
      FROM 
       Followers f 
      WHERE 
       f.followerid = user14_.Id) as formula0_6_, 
      websites15_.USERID as USERID16_, 
      website16_.ID as WEBSITEID16_, 
      website16_.ID as ID6_7_, 
      website16_.ACTIVE as ACTIVE6_7_, 
      website16_.DATECREATED as DATECREA3_6_7_, 
      website16_.DATEMODIFIED as DATEMODI4_6_7_, 
      website16_.DESCRIPTION as DESCRIPT5_6_7_, 
      website16_.NAME as NAME6_7_, 
      website16_.URL as URL6_7_, 
      uc1_.USERID as USERID17_, 
      uc1_.ID as ID17_, 
      uc1_.ID as ID17_8_, 
      uc1_.ACTIVE as ACTIVE17_8_, 
      uc1_.CONNECTORID as CONNECTO6_17_8_, 
      uc1_.dateCreated as dateCrea3_17_8_, 
      uc1_.dateModified as dateModi4_17_8_, 
      uc1_.META as META17_8_, 
      uc1_.USERID as USERID17_8_, 
      connector18_.ID as ID18_9_, 
      connector18_.ACTIVE as ACTIVE18_9_, 
      connector18_.DATECREATED as DATECREA3_18_9_, 
      connector18_.DISPLAYNAME as DISPLAYN4_18_9_, 
      connector18_.NAME as NAME18_9_, 
      user19_.ID as ID0_10_, 
      user19_.BIOGRAPHY as BIOGRAPHY0_10_, 
      user19_.DATECREATED as DATECREA3_0_10_, 
      user19_.EMAIL as EMAIL0_10_, 
      user19_.ENABLED as ENABLED0_10_, 
      user19_.FIRSTNAME as FIRSTNAME0_10_, 
      user19_.HIDECONNECTORS as HIDECONN7_0_10_, 
      user19_.HIDEEMAIL as HIDEEMAIL0_10_, 
      user19_.HIDENAME as HIDENAME0_10_, 
      user19_.LASTNAME as LASTNAME0_10_, 
      user19_.PASSWORD as PASSWORD0_10_, 
      user19_.SALT as SALT0_10_, 
      user19_.TITLE as TITLE0_10_, 
      user19_.USERNAME as USERNAME0_10_, 
      user19_.WARNINGS as WARNINGS0_10_, 
      (SELECT 
       COUNT(*) 
      FROM 
       Followers f 
      WHERE 
       f.followerid = user19_.Id) as formula0_10_ 
     from 
      REWARD.USERS this_ 
     left outer join 
      UserAssets assets6_ 
       on this_.ID=assets6_.USERID 
     left outer join 
      REWARD.ASSETS asset7_ 
       on assets6_.ASSETID=asset7_.ID 
     left outer join 
      UserRoles roles8_ 
       on this_.ID=roles8_.USERID 
     left outer join 
      REWARD.ROLES role9_ 
       on roles8_.ROLEID=role9_.ID 
     left outer join 
      REWARD.USERBADGES ub2_ 
       on this_.ID=ub2_.USERID 
     left outer join 
      REWARD.BADGELEVELS bl3_ 
       on ub2_.BADGELEVELID=bl3_.ID 
     left outer join 
      REWARD.ASSETS asset12_ 
       on bl3_.ASSETID=asset12_.ID 
     left outer join 
      REWARD.BADGES b4_ 
       on bl3_.BADGEID=b4_.ID 
     left outer join 
      REWARD.USERS user14_ 
       on ub2_.USERID=user14_.ID 
     left outer join 
      UserWebsites websites15_ 
       on user14_.ID=websites15_.USERID 
     left outer join 
      REWARD.WEBSITES website16_ 
       on websites15_.WEBSITEID=website16_.ID 
     left outer join 
      REWARD.USERCONNECTORS uc1_ 
       on this_.ID=uc1_.USERID 
     left outer join 
      REWARD.CONNECTORS connector18_ 
       on uc1_.CONNECTORID=connector18_.ID 
     left outer join 
      REWARD.USERS USER19_ 
       on uc1_.USERID=user19_.ID 
     WHERE 
      this_.ID=10100 
      and this_.ENABLED=1 
      AND UC1_.ACTIVE=1 
      AND UB2_.VISIBLE=1 
      and bl3_.ACTIVE=1 
      AND b4_.ACTIVE=1 
      AND B4_.STATUS='A' 

Answer 1

這些用戶就回來，但他們回來爲空的所有列，其中左連接也沒找到合適的連接表中返回。

由於ANSI空值是如何工作的 b4_.ACTIVE = 1將是這些記錄無效的，因爲空<> 1

嘗試重組你在那裏塊如下：

AND (b4_.ACTIVE=1 or b4_.ACTIVE is null) 
    AND (B4_.STATUS='A' or B4_.STATUS is null) 
    AND (UB2_.VISIBLE=1 or UB2_.VISIBLE is null) 
    and (bl3_.ACTIVE=1 or bl3_.ACTIVE is null) 

另一種方式來解決這是爲左連接添加先決條件。你可以像我一樣做下面的事情，它會排除徽章，其中活動<> 1（不包括壞徽章），並仍然返回所有用戶。

left outer join 
     REWARD.BADGES b4_ 
      on bl3_.BADGEID=b4_.ID 
       AND b4_.ACTIVE=1