Question

I have a main table that I must get data from. I have a left outer join where the fields will match 40% of the time. And then I have another join where I need to match the data from table A with.

This is the SQL in pseudo code. This query won’t work.

— This is the part I want to do but doesn’t work. AND H.COL3 = A.STATE????

I am working with IBM DB2.

SELECT DISTINCT   APP_NO as app_no,   A.STATE as state   ...   ... Fields   ... FROM    TABLE_A A LEFT OUTER JOIN     TABLE_B HIST ON   HIST.COL1 = A.COL1 , TABLE_C B   LEFT OUTER JOIN   TABLE_D H   ON   H.COL2 = B.COL2 -- This is the part I want to do but doesn't work. AND   H.COL3 = A.STATE???? WHERE   A.BRANCH = 'Data' 

Answer 1

I think you could re-write it like this (but I could be reading your statement wrong)

FROM    TABLE_A A LEFT OUTER JOIN TABLE_B HIST ON       HIST.COL1 = A.COL1   LEFT OUTER JOIN TABLE_D H ON        H.COL3 = A.STATE   LEFT OUTER JOIN TABLE_C B ON H.COL2 = B.COL2 WHERE   A.BRANCH = 'Data' 

Also, the IBM doco on this error states:

An ON clause associated with a JOIN operator or in a MERGE statement is not valid. Explanation:

Column references in an ON clause must only reference columns of tables that are in the scope of the ON clause.

So I could be mistaken, it just looks like the erronous ON clause when outer joining ‘H.COL3 = A.STATE’ is out of scope of the On clause because the table A is not in that scope.