I have tried changing it to AND but is still not working. It still gives an compile with warning error. Also it does not allow insertion of data giving a message that the trigger is not valid.

Most replies that I got advised me to not use a trigger but instead use view with calculated columns.

But what I want to know is why is this not working? I am thankful to people for suggesting me a workaround with views but in this phase of learning I am more interested in why the trigger is not working? What have I done wrong? How can I correct it for the trigger to work?

I am using Oracle 11g XE