topic Re: FULL OUTER JOIN in ABAP SQL? in ABAP Forum

FULL OUTER JOIN in ABAP SQL?

Sandra_Rossi — Fri, 13 Mar 2026 14:31:42 GMT

FULL OUTER JOIN is still not permitted directly in ABAP 7.58 (ABAP Keyword Documentation: SELECT, FROM JOIN).

What I'd like to do:

What is the most simple workaround?

Thanks.

Sandra

Re: FULL OUTER JOIN in ABAP SQL?

Sandra_Rossi — Fri, 13 Mar 2026 14:39:02 GMT

The most simple workaround is via a CTE (WITH), UNION DISTINCT (UNION, DISTINCT) and two LEFT OUTER JOIN (see "Result set for outer joins"):

TYPES: BEGIN OF ty_full_outer_join, ebeln TYPE ebeln, ebelp TYPE ebelp, zekkn TYPE dzekkn, bewtp TYPE ekbe-bewtp, loekz TYPE ekkn-loekz, END OF ty_full_outer_join. TYPES tt_full_outer_join TYPE STANDARD TABLE OF ty_full_outer_join WITH EMPTY KEY. DATA(itab) = VALUE tt_full_outer_join( ). WITH +union AS ( SELECT ebeln, ebelp, zekkn FROM ekbe UNION DISTINCT SELECT ebeln, ebelp, zekkn FROM ekkn ) SELECT +union~ebeln, +union~ebelp, +union~zekkn, ekbe~bewtp, ekkn~loekz FROM +union LEFT OUTER JOIN ekbe ON ekbe~ebeln = +union~ebeln AND ekbe~ebelp = +union~ebelp AND ekbe~zekkn = +union~zekkn LEFT OUTER JOIN ekkn ON ekkn~ebeln = +union~ebeln AND ekkn~ebelp = +union~ebelp AND ekkn~zekkn = +union~zekkn WHERE ... INTO TABLE @itab.

Re: FULL OUTER JOIN in ABAP SQL?

BiberM — Sat, 14 Mar 2026 08:05:16 GMT

Hi Sandra,

yes, this would hve been my solution, too. Would this be possible without the CTE?

Another solution would be AMDP as HANA does Support a FULL OUTER JOIN.

Best regards

Michael

Re: FULL OUTER JOIN in ABAP SQL?

Sandra_Rossi — Sat, 14 Mar 2026 11:10:24 GMT

I guess it's possible without the CTE, but it will be less elegant, less legible.

If you find a solution without the CTE, please post it as another solution.

Re: FULL OUTER JOIN in ABAP SQL?

BiberM — Mon, 16 Mar 2026 14:22:41 GMT

Hi,

I just tried the following in our dev system with very limited data (4-digit line count in each table). The performance was .... I just did one run.

SELECT coalesce( ekbe~ebeln, ekkn~ebeln ) as ebeln, coalesce( ekbe~ebelp, ekkn~ebelp ) as ebelp, coalesce( ekbe~zekkn, ekkn~zekkn ) as zekkn, ekbe~bewtp, ekkn~loekz FROM ekbe LEFT OUTER JOIN ekkn ON ekbe~ebeln = ekkn~ebeln AND ekbe~ebelp = ekkn~ebelp AND ekbe~zekkn = ekkn~zekkn * WHERE ... UNION SELECT coalesce( ekbe~ebeln, ekkn~ebeln ) as ebeln, coalesce( ekbe~ebelp, ekkn~ebelp ) as ebelp, coalesce( ekbe~zekkn, ekkn~zekkn ) as zekkn, ekbe~bewtp, ekkn~loekz FROM ekkn LEFT OUTER JOIN ekbe ON ekbe~ebeln = ekkn~ebeln AND ekbe~ebelp = ekkn~ebelp AND ekbe~zekkn = ekkn~zekkn * WHERE ... INTO TABLE @DATA(lt_result). out->write( lt_result ).

The idea is to do both "parts" of a FULL OUTER JOIN seperately and then unite them with a UNION. This one especially without the ALL addition in order to remove the duplicates which are the datasets which exists in both tables.

Best regards
Michael

Re: FULL OUTER JOIN in ABAP SQL?

HermannGahm — Thu, 02 Apr 2026 12:46:25 GMT

Hi,

yes this is what i would have suggested as well,

Just with left and right outer in the union branches , see below.

Depending on the database (or engines) used the union branches might be executed in parallel.
In my case the select returns 323 records (EKBE 3211 records EKKN 582 records) in 6.5 ms. The
UNION branches are executed in parallel.

With larger volumes (EKBE 20,001,016 rows and 117,896,463) it returns 8345 records in 160 ms.

Kind regards,

Hermann

SELECT COALESCE( ekkn~ebeln, ekbe~ebeln ) AS ebeln, COALESCE( ekkn~ebelp, ekbe~ebelp ) AS ebelp, COALESCE( ekkn~zekkn, ekbe~zekkn ) AS zekkn, ekbe~bewtp, ekkn~loekz FROM ekbe LEFT OUTER JOIN ekkn " <=== FULL not valid in ABAP SQL ON ekkn~ebeln = ekbe~ebeln AND ekkn~ebelp = ekbe~ebelp AND ekkn~zekkn = ekbe~zekkn WHERE ekbe~gjahr = '2026' UNION SELECT COALESCE( ekkn~ebeln, ekbe~ebeln ) AS ebeln, COALESCE( ekkn~ebelp, ekbe~ebelp ) AS ebelp, COALESCE( ekkn~zekkn, ekbe~zekkn ) AS zekkn, ekbe~bewtp, ekkn~loekz FROM ekbe RIGHT OUTER JOIN ekkn " <=== FULL not valid in ABAP SQL ON ekkn~ebeln = ekbe~ebeln AND ekkn~ebelp = ekbe~ebelp AND ekkn~zekkn = ekbe~zekkn WHERE ekkn~aedat = '20260101' INTO TABLE (itab).