Change a specific field in an SAP database table
Changing a values within a database table using the UPDATE command is very useful function to perform. Althouygh if you want to update a number of fields in the table you may want to use the MODIFY command.
data: ld_ebeln type ekko-ebeln. update EKKO set ERNAM = sy-uname where ebeln = ld_ebeln.
Also see here for example abap program which uses the UPDATE command to update a database field directly