i need some help i am a dba not a programmer.

i am creating a trigger that will update table a after an insert or update . this trigger will update 2 columns to equal table b when table a primary key = table b primary key.

create or replace trigger test
after insert or update on table a
for each row
update table a
set tablea.column1 = tableb.column1,
tablea.column2 = tableb.column2
where tablea.idno = tableb.idno