Is it worth it to check for duplicates when adding a record with a unique hash to the database?

Question

PHP

Let's take an example.
In one unnamed database table, there is a hash field containing a unique set of characters automatically generated for each record before it is added to the database. Should I check for records with the same hash before adding a record? If yes, how? a while loop? Is this 0.0000000000001% chance worth it?

Answer 1

If at all this situation (coincidence) is handled, then it is better to make this field a unique constraint, and if an error occurs when adding a record, try another hash.