Record Check In Different Tables

I have a database with two tables:

Table 1: Human
Table 2: Exempt

I have created the following code for creating a record, which works fine. But what I would like to do is to check if I add a record on the "Human" table to verify if the record number already exists on the "Exempt" table. I have already created an error handler for it to check if it exists within the same table which works fine. But I can get to do the rest. I created a separate file where I created two functions, but I don't think I did it right. Code: