insert_query = """
        INSERT OR REPLACE INTO users (id, name, email, age)
        VALUES (?, ?, ?, ?)
 """

SQLiteでは、以下の3つの書き方はすべて同じ

-- 1. 標準的
ＩNSERT OR REPLACE INTO users (id, name, email, age) VALUES (?, ?, ?, ?);

-- 2. 短縮形の書き方
REPLACE INTO users (id, name, email, age) VALUES (?, ?, ?, ?);

-- 3. PostgreSQL等に近い、衝突時の挙動を明記する書き方 (SQLite 3.24.0以降)
ＩNSERT INTO users (id, name, email, age) VALUES (?, ?, ?, ?)
ON CONFLICT(id) DO UPDATE SET name=excluded.name, email=excluded.email, age=excluded.age;

CASCADE設定がある場合、の ON CONFLICT を使う