This ABAP statement works in a similar way to APPEND and inserts the contents of a work area into an internal table.
But instead of simply adding to the end of the itab, it first checks for entries with the same key
and then adds to the numeric values of existing row with that same key.
Please note: The key is made up of all fields before numeric field and they must all be the same!
Here is and example ABAP code snipet that demonstrates the use of the COLLECT statement
data: it_ekko type STANDARD TABLE OF ekko, wa_ekko like line of it_ekko. COLLECT wa_ekko into it_ekko.