You mean check existing records before INSERTI NTO (transfer from TableIzlezDneven to Tablelzlez) or after INSERT INTO.

Let me clarify what exactly this is about.
It is a restaurant program, where all orders in the restaurant are recorded in TableIzlezDneven during per one day.
At the...

No TableIzlez is not empty.
That table is  fill from TableIzlezDneven every day (one time) and TableIzlezDneven is deleted one time per day , and next day start TableIzlezDneven empty.