sql - ORA-00927: missing equal sign -

im creating first sql trigger,

create or replace trigger totalsalary     after insert on employee     each row when ( new.dno not null ) begin     update department     set totalsalary totalsalary + new.salary     dno = new.dno; end ; 

but got error message , dont know how fix it

error @ line 3: pl/sql: ora-00927: missing equal sign  1. create or replace trigger sueldototal 2.  after insert on empleado 3.  each row 4. when ( new.dno not null ) 5. begin 

set totalsalary totalsalary + new.salary

you have missing equal sign in set clause.

create or replace trigger totalsalary     after insert on employee     each row when ( new.dno not null ) begin     update department     set totalsalary = totalsalary + :new.salary     dno = :new.dno; end; / 

new.salary

also, incorrect while referencing old , new values:

:new.salary