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  4. OR in a JOIN

OR in a JOIN

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  • P PIEBALDconsult

    I'm having some trouble with a JOIN that involves an OR (in SQL Server). For example:

    SELECT *
    FROM TableA A
    INNER JOIN TableB B
    ON A.Field1=B.Field1
    OR A.Field2=B.Field2

    Quite correctly this produces two output rows for each row in TableA that matches TableB via both Field1 and Field2* -- but for this JOIN I want to output only one row when both match (preferably the result of the Field1 match, and only report the Field2 match if Field1 doesn't match). * Clarification -- when it matches two rows in TableB; one via Field1 and the other via Field2. I haven't done much searching for pointers because I don't think it's possible, however I'm posting here just in case someone here knows of a way or a simple (SQL only) work-around. Edit -- Here's an example:

    SELECT * FROM TableA

    ID Field1 Field2


    10 A E
    11 E D
    12 A D

    SELECT * FROM TableB

    ID Field1 Field2


    20 A B
    21 C D

    10 will match only 20 ; 11 will match only 21 ; 12 will match both 20 and 21 -- so I want 20.

    ID Field1 Field2 ID Field1 Field2
    10 A E 20 A B <-- I want this row
    11 E D 21 C D <-- I want this row
    12 A D 20 A B <-- I want this row
    12 A D 21 C D <-- I don't want this row

    Luc's and pmpdesign's suggestions yield the same output. Here's a variation of Bernhard's suggestion, which seems to work:

    WITH cte1 AS
    (
    SELECT A.ID aID
    , A.Field1 aField1
    , A.Field2 aField2
    , B.ID bID
    , B.Field1 bField1
    , B.Field2 bField2
    FROM TableA A
    INNER JOIN TableB B
    ON A.Field1=B.Field1
    )
    , cte2 AS
    (
    SELECT A.ID aID
    , A.Field1 aField1
    , A.Field2 aField2
    , B.ID bID
    , B.Field1 bField1
    , B.Field2 bField2
    FROM TableA A
    INNER JOIN TableB B
    ON A.Field2=B.Field2
    )
    SELECT *
    FROM cte1
    UNION ALL
    SELECT C2.*
    FROM cte2 C2
    LEFT OUTER JOIN cte1 C1
    ON C2.aID=C1.aID
    WHERE C1.aID IS NULL

    P Offline
    P Offline
    pmpdesign
    wrote on last edited by
    #9

    Without a dataset I can't be sure, but have you tried

    SELECT DISTINCT * FROM...

    P 1 Reply Last reply
    0
    • P PIEBALDconsult

      I'm having some trouble with a JOIN that involves an OR (in SQL Server). For example:

      SELECT *
      FROM TableA A
      INNER JOIN TableB B
      ON A.Field1=B.Field1
      OR A.Field2=B.Field2

      Quite correctly this produces two output rows for each row in TableA that matches TableB via both Field1 and Field2* -- but for this JOIN I want to output only one row when both match (preferably the result of the Field1 match, and only report the Field2 match if Field1 doesn't match). * Clarification -- when it matches two rows in TableB; one via Field1 and the other via Field2. I haven't done much searching for pointers because I don't think it's possible, however I'm posting here just in case someone here knows of a way or a simple (SQL only) work-around. Edit -- Here's an example:

      SELECT * FROM TableA

      ID Field1 Field2


      10 A E
      11 E D
      12 A D

      SELECT * FROM TableB

      ID Field1 Field2


      20 A B
      21 C D

      10 will match only 20 ; 11 will match only 21 ; 12 will match both 20 and 21 -- so I want 20.

      ID Field1 Field2 ID Field1 Field2
      10 A E 20 A B <-- I want this row
      11 E D 21 C D <-- I want this row
      12 A D 20 A B <-- I want this row
      12 A D 21 C D <-- I don't want this row

      Luc's and pmpdesign's suggestions yield the same output. Here's a variation of Bernhard's suggestion, which seems to work:

      WITH cte1 AS
      (
      SELECT A.ID aID
      , A.Field1 aField1
      , A.Field2 aField2
      , B.ID bID
      , B.Field1 bField1
      , B.Field2 bField2
      FROM TableA A
      INNER JOIN TableB B
      ON A.Field1=B.Field1
      )
      , cte2 AS
      (
      SELECT A.ID aID
      , A.Field1 aField1
      , A.Field2 aField2
      , B.ID bID
      , B.Field1 bField1
      , B.Field2 bField2
      FROM TableA A
      INNER JOIN TableB B
      ON A.Field2=B.Field2
      )
      SELECT *
      FROM cte1
      UNION ALL
      SELECT C2.*
      FROM cte2 C2
      LEFT OUTER JOIN cte1 C1
      ON C2.aID=C1.aID
      WHERE C1.aID IS NULL

      B Offline
      B Offline
      Bernhard Hiller
      wrote on last edited by
      #10

      A complicated UNION:

      SELECT *
      FROM TableA A
      INNER JOIN TableB B
      ON A.Field1=B.Field1
      UNION
      SELECT *
      FROM TableA A
      INNER JOIN TableB B
      ON A.Field2=B.Field2
      WHERE A.ID NOT IN
      (
      SELECT ID
      FROM TableA A
      INNER JOIN TableB B
      ON A.Field1=B.Field1
      )

      assuming that ID is the primary key of TableA.

      P 1 Reply Last reply
      0
      • P pmpdesign

        Without a dataset I can't be sure, but have you tried

        SELECT DISTINCT * FROM...

        P Offline
        P Offline
        PIEBALDconsult
        wrote on last edited by
        #11

        No, that won't work -- the two resultant rows are distinct.

        1 Reply Last reply
        0
        • B Bernhard Hiller

          A complicated UNION:

          SELECT *
          FROM TableA A
          INNER JOIN TableB B
          ON A.Field1=B.Field1
          UNION
          SELECT *
          FROM TableA A
          INNER JOIN TableB B
          ON A.Field2=B.Field2
          WHERE A.ID NOT IN
          (
          SELECT ID
          FROM TableA A
          INNER JOIN TableB B
          ON A.Field1=B.Field1
          )

          assuming that ID is the primary key of TableA.

          P Offline
          P Offline
          PIEBALDconsult
          wrote on last edited by
          #12

          Possibly, but no, no primary key. Tried it, and it seems to work. :thumbsup: It may take a while to run on the data though. :sigh:

          1 Reply Last reply
          0
          • P Paul Conrad

            Do you have a sample data set that you are using?

            ""Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

            P Offline
            P Offline
            PIEBALDconsult
            wrote on last edited by
            #13

            I'll cobble something up.

            P 1 Reply Last reply
            0
            • P PIEBALDconsult

              I'm having some trouble with a JOIN that involves an OR (in SQL Server). For example:

              SELECT *
              FROM TableA A
              INNER JOIN TableB B
              ON A.Field1=B.Field1
              OR A.Field2=B.Field2

              Quite correctly this produces two output rows for each row in TableA that matches TableB via both Field1 and Field2* -- but for this JOIN I want to output only one row when both match (preferably the result of the Field1 match, and only report the Field2 match if Field1 doesn't match). * Clarification -- when it matches two rows in TableB; one via Field1 and the other via Field2. I haven't done much searching for pointers because I don't think it's possible, however I'm posting here just in case someone here knows of a way or a simple (SQL only) work-around. Edit -- Here's an example:

              SELECT * FROM TableA

              ID Field1 Field2


              10 A E
              11 E D
              12 A D

              SELECT * FROM TableB

              ID Field1 Field2


              20 A B
              21 C D

              10 will match only 20 ; 11 will match only 21 ; 12 will match both 20 and 21 -- so I want 20.

              ID Field1 Field2 ID Field1 Field2
              10 A E 20 A B <-- I want this row
              11 E D 21 C D <-- I want this row
              12 A D 20 A B <-- I want this row
              12 A D 21 C D <-- I don't want this row

              Luc's and pmpdesign's suggestions yield the same output. Here's a variation of Bernhard's suggestion, which seems to work:

              WITH cte1 AS
              (
              SELECT A.ID aID
              , A.Field1 aField1
              , A.Field2 aField2
              , B.ID bID
              , B.Field1 bField1
              , B.Field2 bField2
              FROM TableA A
              INNER JOIN TableB B
              ON A.Field1=B.Field1
              )
              , cte2 AS
              (
              SELECT A.ID aID
              , A.Field1 aField1
              , A.Field2 aField2
              , B.ID bID
              , B.Field1 bField1
              , B.Field2 bField2
              FROM TableA A
              INNER JOIN TableB B
              ON A.Field2=B.Field2
              )
              SELECT *
              FROM cte1
              UNION ALL
              SELECT C2.*
              FROM cte2 C2
              LEFT OUTER JOIN cte1 C1
              ON C2.aID=C1.aID
              WHERE C1.aID IS NULL

              C Offline
              C Offline
              Chris Meech
              wrote on last edited by
              #14

              To have the duplicates removed, I think a union would do that.

              SELECT *
              FROM TableA A
              INNER JOIN TableB B
              ON A.Field1=B.Field1
              UNION
              SELECT *
              FROM TableA A
              INNER JOIN TableB B
              ON A.Field1<>B.Field1 AND A.Field2=B.Field2
              ;

              Try that. :)

              Chris Meech I am Canadian. [heard in a local bar] In theory there is no difference between theory and practice. In practice there is. [Yogi Berra] posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]

              P 1 Reply Last reply
              0
              • C Chris Meech

                To have the duplicates removed, I think a union would do that.

                SELECT *
                FROM TableA A
                INNER JOIN TableB B
                ON A.Field1=B.Field1
                UNION
                SELECT *
                FROM TableA A
                INNER JOIN TableB B
                ON A.Field1<>B.Field1 AND A.Field2=B.Field2
                ;

                Try that. :)

                Chris Meech I am Canadian. [heard in a local bar] In theory there is no difference between theory and practice. In practice there is. [Yogi Berra] posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]

                P Offline
                P Offline
                PIEBALDconsult
                wrote on last edited by
                #15

                I think that's basically what Luc suggested -- and it doesn't work.

                C 1 Reply Last reply
                0
                • P PIEBALDconsult

                  I think that's basically what Luc suggested -- and it doesn't work.

                  C Offline
                  C Offline
                  Chris Meech
                  wrote on last edited by
                  #16

                  It's similar to what other's have suggested except that it's a union of the two result sets, which should eliminate any duplicates.

                  Chris Meech I am Canadian. [heard in a local bar] In theory there is no difference between theory and practice. In practice there is. [Yogi Berra] posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]

                  P 1 Reply Last reply
                  0
                  • P PIEBALDconsult

                    I'll cobble something up.

                    P Offline
                    P Offline
                    Paul Conrad
                    wrote on last edited by
                    #17

                    If it is possible, that would be cool so there can be a data set to test against and see what the expected results are :)

                    ""Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

                    P 1 Reply Last reply
                    0
                    • C Chris Meech

                      It's similar to what other's have suggested except that it's a union of the two result sets, which should eliminate any duplicates.

                      Chris Meech I am Canadian. [heard in a local bar] In theory there is no difference between theory and practice. In practice there is. [Yogi Berra] posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]

                      P Offline
                      P Offline
                      PIEBALDconsult
                      wrote on last edited by
                      #18

                      Chris Meech wrote:

                      should eliminate any duplicates.

                      Except it doesn't. I have added some clarification and sample data to my post.

                      C 1 Reply Last reply
                      0
                      • P Paul Conrad

                        If it is possible, that would be cool so there can be a data set to test against and see what the expected results are :)

                        ""Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

                        P Offline
                        P Offline
                        PIEBALDconsult
                        wrote on last edited by
                        #19

                        I added it to the post with some clarification.

                        P 1 Reply Last reply
                        0
                        • P PIEBALDconsult

                          I added it to the post with some clarification.

                          P Offline
                          P Offline
                          Paul Conrad
                          wrote on last edited by
                          #20

                          Coolness! I will check it out soon and see if there's anything I can add to this thread in terms of a solution :)

                          ""Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

                          1 Reply Last reply
                          0
                          • P PIEBALDconsult

                            I'm having some trouble with a JOIN that involves an OR (in SQL Server). For example:

                            SELECT *
                            FROM TableA A
                            INNER JOIN TableB B
                            ON A.Field1=B.Field1
                            OR A.Field2=B.Field2

                            Quite correctly this produces two output rows for each row in TableA that matches TableB via both Field1 and Field2* -- but for this JOIN I want to output only one row when both match (preferably the result of the Field1 match, and only report the Field2 match if Field1 doesn't match). * Clarification -- when it matches two rows in TableB; one via Field1 and the other via Field2. I haven't done much searching for pointers because I don't think it's possible, however I'm posting here just in case someone here knows of a way or a simple (SQL only) work-around. Edit -- Here's an example:

                            SELECT * FROM TableA

                            ID Field1 Field2


                            10 A E
                            11 E D
                            12 A D

                            SELECT * FROM TableB

                            ID Field1 Field2


                            20 A B
                            21 C D

                            10 will match only 20 ; 11 will match only 21 ; 12 will match both 20 and 21 -- so I want 20.

                            ID Field1 Field2 ID Field1 Field2
                            10 A E 20 A B <-- I want this row
                            11 E D 21 C D <-- I want this row
                            12 A D 20 A B <-- I want this row
                            12 A D 21 C D <-- I don't want this row

                            Luc's and pmpdesign's suggestions yield the same output. Here's a variation of Bernhard's suggestion, which seems to work:

                            WITH cte1 AS
                            (
                            SELECT A.ID aID
                            , A.Field1 aField1
                            , A.Field2 aField2
                            , B.ID bID
                            , B.Field1 bField1
                            , B.Field2 bField2
                            FROM TableA A
                            INNER JOIN TableB B
                            ON A.Field1=B.Field1
                            )
                            , cte2 AS
                            (
                            SELECT A.ID aID
                            , A.Field1 aField1
                            , A.Field2 aField2
                            , B.ID bID
                            , B.Field1 bField1
                            , B.Field2 bField2
                            FROM TableA A
                            INNER JOIN TableB B
                            ON A.Field2=B.Field2
                            )
                            SELECT *
                            FROM cte1
                            UNION ALL
                            SELECT C2.*
                            FROM cte2 C2
                            LEFT OUTER JOIN cte1 C1
                            ON C2.aID=C1.aID
                            WHERE C1.aID IS NULL

                            P Offline
                            P Offline
                            Paul Conrad
                            wrote on last edited by
                            #21

                            PIEBALDconsult wrote:

                            so I want 20

                            Do you want 20 in both rows with the Id from Table A being 10, and 12?

                            ""Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

                            P 1 Reply Last reply
                            0
                            • P PIEBALDconsult

                              Chris Meech wrote:

                              should eliminate any duplicates.

                              Except it doesn't. I have added some clarification and sample data to my post.

                              C Offline
                              C Offline
                              Chris Meech
                              wrote on last edited by
                              #22

                              It will remove the duplicates of the resultant set, but now that I've read your example, that is not quite what you are after. In your example once the row with ID 12 from table A matched on FieldA for the row with ID 20, you don't want to include it anymore where it might match on FieldB.

                              Chris Meech I am Canadian. [heard in a local bar] In theory there is no difference between theory and practice. In practice there is. [Yogi Berra] posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]

                              1 Reply Last reply
                              0
                              • P Paul Conrad

                                PIEBALDconsult wrote:

                                so I want 20

                                Do you want 20 in both rows with the Id from Table A being 10, and 12?

                                ""Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

                                P Offline
                                P Offline
                                PIEBALDconsult
                                wrote on last edited by
                                #23

                                Yes.

                                1 Reply Last reply
                                0
                                • P PIEBALDconsult

                                  I'm having some trouble with a JOIN that involves an OR (in SQL Server). For example:

                                  SELECT *
                                  FROM TableA A
                                  INNER JOIN TableB B
                                  ON A.Field1=B.Field1
                                  OR A.Field2=B.Field2

                                  Quite correctly this produces two output rows for each row in TableA that matches TableB via both Field1 and Field2* -- but for this JOIN I want to output only one row when both match (preferably the result of the Field1 match, and only report the Field2 match if Field1 doesn't match). * Clarification -- when it matches two rows in TableB; one via Field1 and the other via Field2. I haven't done much searching for pointers because I don't think it's possible, however I'm posting here just in case someone here knows of a way or a simple (SQL only) work-around. Edit -- Here's an example:

                                  SELECT * FROM TableA

                                  ID Field1 Field2


                                  10 A E
                                  11 E D
                                  12 A D

                                  SELECT * FROM TableB

                                  ID Field1 Field2


                                  20 A B
                                  21 C D

                                  10 will match only 20 ; 11 will match only 21 ; 12 will match both 20 and 21 -- so I want 20.

                                  ID Field1 Field2 ID Field1 Field2
                                  10 A E 20 A B <-- I want this row
                                  11 E D 21 C D <-- I want this row
                                  12 A D 20 A B <-- I want this row
                                  12 A D 21 C D <-- I don't want this row

                                  Luc's and pmpdesign's suggestions yield the same output. Here's a variation of Bernhard's suggestion, which seems to work:

                                  WITH cte1 AS
                                  (
                                  SELECT A.ID aID
                                  , A.Field1 aField1
                                  , A.Field2 aField2
                                  , B.ID bID
                                  , B.Field1 bField1
                                  , B.Field2 bField2
                                  FROM TableA A
                                  INNER JOIN TableB B
                                  ON A.Field1=B.Field1
                                  )
                                  , cte2 AS
                                  (
                                  SELECT A.ID aID
                                  , A.Field1 aField1
                                  , A.Field2 aField2
                                  , B.ID bID
                                  , B.Field1 bField1
                                  , B.Field2 bField2
                                  FROM TableA A
                                  INNER JOIN TableB B
                                  ON A.Field2=B.Field2
                                  )
                                  SELECT *
                                  FROM cte1
                                  UNION ALL
                                  SELECT C2.*
                                  FROM cte2 C2
                                  LEFT OUTER JOIN cte1 C1
                                  ON C2.aID=C1.aID
                                  WHERE C1.aID IS NULL

                                  L Offline
                                  L Offline
                                  Luc Pattyn
                                  wrote on last edited by
                                  #24

                                  Your modified message is much clearer. And this is what works for me:

                                  SELECT * FROM TableA A INNER JOIN TableB B ON A.Field1=B.Field1
                                  UNION ALL
                                  SELECT * FROM TableA A INNER JOIN TableB B ON A.Field2=B.Field2
                                  WHERE NOT A.ID IN (SELECT A.ID FROM TableA A INNER JOIN TableB B ON A.Field1=B.Field1)

                                  just 3 SELECTs, no LEFT PS: I failed to get it to work with a CTE on SQL Server... :)

                                  Luc Pattyn [My Articles] Nil Volentibus Arduum

                                  B 1 Reply Last reply
                                  0
                                  • P PIEBALDconsult

                                    I'm having some trouble with a JOIN that involves an OR (in SQL Server). For example:

                                    SELECT *
                                    FROM TableA A
                                    INNER JOIN TableB B
                                    ON A.Field1=B.Field1
                                    OR A.Field2=B.Field2

                                    Quite correctly this produces two output rows for each row in TableA that matches TableB via both Field1 and Field2* -- but for this JOIN I want to output only one row when both match (preferably the result of the Field1 match, and only report the Field2 match if Field1 doesn't match). * Clarification -- when it matches two rows in TableB; one via Field1 and the other via Field2. I haven't done much searching for pointers because I don't think it's possible, however I'm posting here just in case someone here knows of a way or a simple (SQL only) work-around. Edit -- Here's an example:

                                    SELECT * FROM TableA

                                    ID Field1 Field2


                                    10 A E
                                    11 E D
                                    12 A D

                                    SELECT * FROM TableB

                                    ID Field1 Field2


                                    20 A B
                                    21 C D

                                    10 will match only 20 ; 11 will match only 21 ; 12 will match both 20 and 21 -- so I want 20.

                                    ID Field1 Field2 ID Field1 Field2
                                    10 A E 20 A B <-- I want this row
                                    11 E D 21 C D <-- I want this row
                                    12 A D 20 A B <-- I want this row
                                    12 A D 21 C D <-- I don't want this row

                                    Luc's and pmpdesign's suggestions yield the same output. Here's a variation of Bernhard's suggestion, which seems to work:

                                    WITH cte1 AS
                                    (
                                    SELECT A.ID aID
                                    , A.Field1 aField1
                                    , A.Field2 aField2
                                    , B.ID bID
                                    , B.Field1 bField1
                                    , B.Field2 bField2
                                    FROM TableA A
                                    INNER JOIN TableB B
                                    ON A.Field1=B.Field1
                                    )
                                    , cte2 AS
                                    (
                                    SELECT A.ID aID
                                    , A.Field1 aField1
                                    , A.Field2 aField2
                                    , B.ID bID
                                    , B.Field1 bField1
                                    , B.Field2 bField2
                                    FROM TableA A
                                    INNER JOIN TableB B
                                    ON A.Field2=B.Field2
                                    )
                                    SELECT *
                                    FROM cte1
                                    UNION ALL
                                    SELECT C2.*
                                    FROM cte2 C2
                                    LEFT OUTER JOIN cte1 C1
                                    ON C2.aID=C1.aID
                                    WHERE C1.aID IS NULL

                                    J Offline
                                    J Offline
                                    Jorgen Andersson
                                    wrote on last edited by
                                    #25

                                    Here's another way to do it:

                                    WITH CTE AS
                                    (
                                    SELECT A.ID aID
                                    ,A.Field1 aField1
                                    ,A.Field2 aField2
                                    ,CASE WHEN L.ID IS NULL THEN R.ID ELSE L.ID end bID
                                    ,CASE WHEN L.Field1 IS NULL THEN R.field1 ELSE L.Field1 END bField1
                                    ,CASE WHEN L.Field2 IS NULL THEN R.Field2 ELSE L.Field2 END bField2
                                    FROM TableB L
                                    right OUTER JOIN TableA A
                                    ON l.field1 = a.field1
                                    left OUTER JOIN TableB R
                                    ON a.field2 = r.field2
                                    )
                                    SELECT aID
                                    ,aField1
                                    ,aField2
                                    ,bID
                                    ,bField1
                                    ,bField2
                                    FROM CTE
                                    WHERE bid IS NOT null

                                    The plan indicates that it should be faster, but that's with dummy data. I'm curious about the performance with real data.

                                    Light moves faster than sound. That is why some people appear bright, until you hear them speak. List of common misconceptions

                                    L 1 Reply Last reply
                                    0
                                    • J Jorgen Andersson

                                      Here's another way to do it:

                                      WITH CTE AS
                                      (
                                      SELECT A.ID aID
                                      ,A.Field1 aField1
                                      ,A.Field2 aField2
                                      ,CASE WHEN L.ID IS NULL THEN R.ID ELSE L.ID end bID
                                      ,CASE WHEN L.Field1 IS NULL THEN R.field1 ELSE L.Field1 END bField1
                                      ,CASE WHEN L.Field2 IS NULL THEN R.Field2 ELSE L.Field2 END bField2
                                      FROM TableB L
                                      right OUTER JOIN TableA A
                                      ON l.field1 = a.field1
                                      left OUTER JOIN TableB R
                                      ON a.field2 = r.field2
                                      )
                                      SELECT aID
                                      ,aField1
                                      ,aField2
                                      ,bID
                                      ,bField1
                                      ,bField2
                                      FROM CTE
                                      WHERE bid IS NOT null

                                      The plan indicates that it should be faster, but that's with dummy data. I'm curious about the performance with real data.

                                      Light moves faster than sound. That is why some people appear bright, until you hear them speak. List of common misconceptions

                                      L Offline
                                      L Offline
                                      Luc Pattyn
                                      wrote on last edited by
                                      #26

                                      Interesting. IMO it can be simplified further, as the CTE isn't really necessary, so I now have:

                                      SELECT A.ID aID
                                      ,A.Field1 aField1
                                      ,A.Field2 aField2
                                      ,CASE WHEN L.ID IS NULL THEN R.ID ELSE L.ID end bID
                                      ,CASE WHEN L.ID IS NULL THEN R.field1 ELSE L.Field1 END bField1
                                      ,CASE WHEN L.ID IS NULL THEN R.Field2 ELSE L.Field2 END bField2
                                      FROM TableB L
                                      RIGHT OUTER JOIN TableA A ON L.Field1 = A.Field1
                                      LEFT OUTER JOIN TableB R ON A.Field2 = R.Field2
                                      WHERE L.ID IS NOT NULL OR R.ID IS NOT NULL

                                      I have your cases depend on the ID field, not the other fields (where null might be valid) :)

                                      Luc Pattyn [My Articles] Nil Volentibus Arduum

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                                      • L Luc Pattyn

                                        Interesting. IMO it can be simplified further, as the CTE isn't really necessary, so I now have:

                                        SELECT A.ID aID
                                        ,A.Field1 aField1
                                        ,A.Field2 aField2
                                        ,CASE WHEN L.ID IS NULL THEN R.ID ELSE L.ID end bID
                                        ,CASE WHEN L.ID IS NULL THEN R.field1 ELSE L.Field1 END bField1
                                        ,CASE WHEN L.ID IS NULL THEN R.Field2 ELSE L.Field2 END bField2
                                        FROM TableB L
                                        RIGHT OUTER JOIN TableA A ON L.Field1 = A.Field1
                                        LEFT OUTER JOIN TableB R ON A.Field2 = R.Field2
                                        WHERE L.ID IS NOT NULL OR R.ID IS NOT NULL

                                        I have your cases depend on the ID field, not the other fields (where null might be valid) :)

                                        Luc Pattyn [My Articles] Nil Volentibus Arduum

                                        J Offline
                                        J Offline
                                        Jorgen Andersson
                                        wrote on last edited by
                                        #27

                                        I'm getting identical plans, but your version is prettier. :-)

                                        Light moves faster than sound. That is why some people appear bright, until you hear them speak. List of common misconceptions

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                                        • L Luc Pattyn

                                          Your modified message is much clearer. And this is what works for me:

                                          SELECT * FROM TableA A INNER JOIN TableB B ON A.Field1=B.Field1
                                          UNION ALL
                                          SELECT * FROM TableA A INNER JOIN TableB B ON A.Field2=B.Field2
                                          WHERE NOT A.ID IN (SELECT A.ID FROM TableA A INNER JOIN TableB B ON A.Field1=B.Field1)

                                          just 3 SELECTs, no LEFT PS: I failed to get it to work with a CTE on SQL Server... :)

                                          Luc Pattyn [My Articles] Nil Volentibus Arduum

                                          B Offline
                                          B Offline
                                          Bernhard Hiller
                                          wrote on last edited by
                                          #28

                                          That's actually my solution posted above - UNION vs. UNION ALL does not make a difference here, because both queries select all columns from the same table.

                                          L 1 Reply Last reply
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