How to write PHP code that insert records in this table without checking the uniqueness of user_id by comparing all user_id present in the table? : <p>I have a table with primary key as user_id. This user _id is a random alphanumeric string of length 6. How to write PHP code that insert records in this table without checking the uniqueness of user_id by comparing all user_id present in the table?</p>
