I received a strange message ORA-0 1403: No data found. Is there a god who knows?

It is possible that the database itself has no data, so it was not found.

Single-step debugging, first add where condition to see if there is data or how much data there is, and then debug once in the process to see where the problem lies.

You can also jump out of storage, and when there is no data, jump out of storage.