SQL trigger doesn’t allow to update

I have trigger trig_1 on racun table. I have some columns in racun table and i created trigger to don’t allow to update column iznos, but when i try to update another column in the same table, trigger doesn’t allow to do that. I tryed to delete and create trig_1 but nothing happend. I created that trigger in SQL 17 but now i am using SQL 18.

ALTER trigger [dbo].[trig_1]
 on [dbo].[racun]
 AFTER UPDATE
 as
 begin
    if update(iznos)
    raiserror('Ne moze ovo', 16, 1)
    rollback
 end

Answer

You should use IF UPDATE statement with UPDATE command in your trigger though.

ALTER trigger [dbo].[trig_1]
 on [dbo].[racun]
 AFTER UPDATE
 as
begin
 if update(iznos)
 begin
    UPDATE [dbo].[racun]
...    
raiserror('Ne moze ovo', 16, 1)
    rollback
 end
end