ABAP SQL join where the joining fields are based on a condition

[former_member636171]

Hi all,

I want to join tables (TAB1 and TAB2) together on two columns depending on whether one of the columns is empty or not.
If TAB1-FIELD1 is not empty then I want to join on FIELD1, else I want to join on FIELD2.

I could do this by selecting TAB1 into an internal table and then doing a select for each line in the table but there must be a better way to do this?

Any help is appreciated.

Thanks,
Birgir

[mateuszadamus]

Hello bsnorrason

Check this out. Have not tested it, though.

SELECT *
  FROM table1
  JOIN table2
    ON ( ( table2~field1 = table1~field1 AND table1~field1 IS NOT NULL )
      OR ( table2~field2 = table1~field2 AND table1~field2 IS NOT NULL ) ).

Kind regards,
Mateusz

[former_member636171]

Thanks, this worked almost flawlessly!
For my use case I had to switch IS NOT NULL for <> ''.

SELECT *
  FROM table1
  JOIN table2
    ON ( ( table2~field1 = table1~field1 AND table1~field1 <> '' )
      OR ( table2~field2 = table1~field2 AND table1~field2 <> '' ) ).