How to insert only one username and password in SQLite database?

Question

I have an application where I have two textfields and a button. In the first textfield I am entering the username of the user and in the second textfield I am entering the p

Answer 1

If I understood your requirement correctly, You can follow the below guideline.

Before inserting the data to the table, You can check if any record is added to the table.
If the count is 0, you can proceed to insert the record, else you can prompt the error.

I think this will be the simplest way to do this.