topic Re: ABAP SQL join where the joining fields are based on a condition in Application Development and Automation Discussions

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

former_member636171 — Wed, 04 Nov 2020 13:46:11 GMT

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

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

MateuszAdamus — Wed, 04 Nov 2020 14:10:05 GMT

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

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

former_member636171 — Wed, 04 Nov 2020 15:23:38 GMT

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 <> '' ) ).