import sqlite3
conn = sqlite3.connect("data.sqlite")
cur = conn.cursor()
cols = [r[1] for r in cur.execute("PRAGMA table_info(matches)")]
print("existing columns:", cols)
if "winner_participant_ids" not in cols:
    cur.execute('ALTER TABLE matches ADD COLUMN winner_participant_ids TEXT DEFAULT "[]"')
    conn.commit()
    print("added column")
else:
    print("column already exists")
conn.close()