Abap SQL question

Question

Hi,
I need to select the set of records only in Table A, but not in Table B. I think that the correct SQL is:
select k~vbeln
into data
from vbak as k
inner join vbfa as f on kvbeln = fvbelv
where f~vbelv is null.
But the following message appears: u201CNo fields from the right-hand table of a LEFT OUTER JOIN may appear in the WHERE condition: u201CF~VBELBu201Du201D.
Thanks in advance,
Ricard.

Answer 1

Hi Oscar & William,
first of all: The database meaning of NULL is that for the field in question no value is stored for an existing record.
In SAP tables we rarely have any NULL values. Only if you extend an existing table, i.e. append a new field, the database will expand the structure but not store INITIAL values for the new field in all records.
Second, just a hint: although the SAP example uses the mystifying ALIAS (AS) addition for joins, it does not help except reducing the code transparency:
SELECT vbak~vbeln
       INTO lw_data
       FROM vbak
       INNER JOIN vbfa ON vbak~vbeln = vbfa~vbelv
       WHERE vbfa~vbelv IS NULL.
    <you can do your process here>
ENDSELECT.
Is 100 % the same. Nevertheless it will never retrieve a single record because vbelv is never stored as a NULL value.
I think this can be solved using a subquery
DATA : lt_data TYPE table of vbak-vbeln.
SELECT vbeln
       INTO  lt_data  
       FROM vbak
       WHERE NOT EXISTS
          ( SELECT * FROM vbfa WHERE vbelv = vbak~vbeln ).
    <you can do your process here>
ENDSELECT.
To be honest: I did not try the code, never played with subqueries though I should do so.
Regards,
Clemens