Bambinos

ActiveRecord.connection.execute and INSERT statement gotcha.

Today I was working with a more complex version of the following code using ActiveRecord:

             
        def find_or_create_user_by_id(id)
            begin
                 user = User.find(id)
            rescue 
                 User.connection.execute("INSERT INTO users (id ) VALUES(#{id})") 
                 user = User.find(id)
            end    
            return user
        end
    

What’s wrong with this?
The second User.find will throw ActiveRecord::RecordNotFound. The problem is that the execute method, doesn’t invalidate cache, so the second User.find will just hit cache (cache created by the first User.find) instead of hitting the database. To solve the problem I had to use User.connection.insert, it invalidates cache so the second User.find hits database. I was hardly able to find any documentation that would describe this behaviour.