For All Entries In vs Left Join

[absakalli]

Hi Experts,

Can you explain, whats the differences between two blocks? Which one should be preferred in which situation?

SELECT mara~matnr
FROM @lt_itab as it
LEFT JOIN mara ON mara~matnr eq it~matnr
INTO TABLE @DATA(lt_matnr).

SELECT matnr
FROM mara
INTO TABLE @DATA(lt_matnr)
FOR ALL ENTRIES IN @lt_itab
WHERE matnr eq lt_itab-matnr.

[Sandra_Rossi]

I guess it's an interview question. In that case, it's more important to know what you think, to have a discussion, because the interviewers want to evaluate your perspicacity.

FROM lt_itab?

Do you mean:

SELECT ...
FROM @lt_itab ...

Avoid FOR ALL ENTRIES anyway.

FOR ALL ENTRIES corresponds to a INNER JOIN.

Recent ABAP versions allow AMDP, FROM @itab, WITH, GTT...