Python psycopg2 check row exists

Question

In Python psycopg2 how can I check if a row exists?

def track_exists(self, track_id):
    cur = self.conn.cursor()
    cur.execute(\"SELECT fma_track_id FRO         


        

Answer 1

Using exists will allow Postgresql to stop searching at the first occurrence in instead of searching until exhausted:

exists_query = '''
    select exists (
        select 1
        from tracks
        where fma_track_id = %s
    )'''
cursor.execute (exists_query, (track_id,))
return cursor.fetchone()[0]

Another advantage is that it will always return a single row containing a boolean value which can be used directly without further interpretation.