Dynamic progressive select in abap

Question

I would create in Abap a dynamic progressive select in a db table.
Es:
(1) my table has 4 key field;
(2) the first select is with all 4 key;
(3) if i don't find a record -> second select with first 3 key fields;
(4) if i don't find a record -> third select with first 2 key fields;
(5) if i don't find a record -> fourth select with only first key field;
(6) if i don't find a record -> raise error.

I must use field symbols, but how? Can you help me about implementation of selects?
Thanks

"I must use field symbols" sounds like this is some kind of homework or exam question. If it is, then please be honest about it and review http://meta.stackexchange.com/questions/10811/how-to-ask-and-answer-homework-questions — vwegert, Sep 04 '12 at 18:23

score 1 · Answer 1 · answered Sep 10 '12 at 13:13

Pseudocode of a naive approach:

SELECT INTO TABLE with all four fields.
IF sy-dbcnt = 0.
    SELECT INTO TABLE with three fields.
    IF sy-dbcnt = 0.
        SELECT INTO TABLE with two fields.
        IF sy-dbcnt = 0.
            SELECT INTO TABLE with one field.
            IF sy-dbcnt = 0.
                MESSAGE TYPE 'E'.
            ENDIF.
        ENDIF.
    ENDIF.
ENDIF.
LOOP AT table ASSIGNING <field_symbol>.
     "do something with the table line in the field symbol
ENDLOOP.

Dynamic progressive select in abap

1 Answers1