Hi Dimas,
When you use FOR ALL ENTRIES, the only way to know for which records the data is fetched is you have to loop the records fetched with FOR ALL ENTRIES and read the other table. Then you can find the unmatched records with SY-SUBRC.
And one more thing, using FOR ALL ENTRIES is also not recommended, please check Siegfried Boes' post in following link and try to use JOINS instead.
Will writing an inner join be better or creating a view?
Regards,
Vijay