选择带偏移量的语句？

Question

I'm trying to use this SELECT statement in ABAP:

  SELECT DISTINCT * FROM  dbtab
     INTO CORRESPONDING FIELDS OF TABLE itab
     WHERE  field1+7(16)  IN s_field1
     AND    field2        IN s_field2.

but I can't use offset for a dbtab column. How can I solve this problem?

I'm trying to avoid loop like

  SELECT DISTINCT * FROM  dbtab
     WHERE  field2        IN s_field2.
       IF field1+7(16)  IN s_field1
           ...
       endif.
  endselect.

Answer 1

You can't use offset in OPEN SQL.

I would recommend to make a SELECT into an internal table and loop over it like this.

SELECT DISTINCT * FROM dbtab
INTO CORRESPONDING FIELDS OF TABLE itab
WHERE field2 IN s_field2.

LOOP AT dbtab into wa_itab.
  IF wa_itab-field1+7(16) IN s_field1
    ...
  ENDIF.
ENDLOOP.

On the other hand I would also define the internal table as SORTED or HASHED or if you prefer try to SORT itab by the field you are making the comparison. Field symbols could be an alternative also.

Hope it helps.

Answer 2

If your policies allow you to you can use probably use an EXECUTE_SQL block instead, for example if you have an Oracle backend, which allows you to leverage native SQL constructs instead of just OPEN SQL. It's a judgement call whether this is justified or not depending on the performance gain. I think it's probably not.

You could also use a LIKE clause, which isn't as efficient as exactly knowing the offset, but would allow you to encapsulate each option with %: WHERE field 1 LIKE '%search_partial%' OR field1 LIKE...

What is the use-case for this, it might be there's a more appropriate option if we have some context.