How to check if a record exists in a database (SQLite)?

Question

Python

I have a sqlite database, it has the following columns: id, name
How can I make sure that the same user cannot log into the database a second time?

Answer 1

cursor = db.execute('SELECT * FROM table_name WHERE (id IS ? AND name IS ?)', (id, name))
row = cursor.fetchone()
if row is None:
    cursor = db.execute('INSERT INTO table_name (id, name) VALUES (?,?)', (id, name))
    db.commit()

Answer 2

Make id a unique key.