The T_user_points table has a user_promotion_code_id column

This column sometimes contains numeric data (linked to the user_promotion_code_id column in the m_promotion_codes table) and sometimes does not.

For example, the current data contains four data as shown below.

user_promotion_code_id
232
231
235
NUll

But if the data something above,
I got the following error.

sqlalchemy.exc.MultipleResultsFound: Multiple rows were found when exactly one was required

The code looks like below, what makes this error happens?

def getuserPoint(userId):
    """
    Points
    """
    if userId is None:
        print("Error: userId is None. Please pass a valid user id.")
        return 0
    
    today = datetime.now()
    

    try:
        subquery = (
            db.session.query(
                T_user_point.acquired_at,
                T_user_point.point,
                M_promotion_code.valid_days,
                T_user_promotion_code.promotion_code_id,
                T_user_point.user_promotion_code_id,
            )
            .join(T_user_promotion_code, T_user_point.user_promotion_code_id == T_user_promotion_code.user_promotion_code_id)
            .join(M_promotion_code, T_user_promotion_code.promotion_code_id == M_promotion_code.promotion_code_id)
            .filter(T_user_point.user_id == userId)
            .subquery()
        )
    except Exception as e:
        print("An error occurred while generating the subquery:", str(e))
        return 0
    
    point_with_valid_days = 0
    point_without_valid_days = 0

    try:
        result = db.session.query(
            subquery.c.acquired_at,
            subquery.c.point,
            subquery.c.valid_days
        ).all()
        print("Subquery Acquisition Date::", subquery.c.acquired_at)
        print("Subquery Points:", subquery.c.point)
        print("Subquery Effective Date:", subquery.c.valid_days)
        print("Subquery Results:", result)
    except Exception as e:
        print("An error occurred while executing the query:", str(e))
        return 0

    for row in result:
        acquired_at = row.acquired_at
        points = row.point
        valid_days = row.valid_days

        if valid_days is not None:
            expiration_date = acquired_at + timedelta(days=valid_days)
            print('Expiration date', expiration_date)
            if today < expiration_date:
                point_with_valid_days += points
            print('point_with_valid_days', point_with_valid_days)
        else:
            point_without_valid_days += 0



    try:
        point_without_valid_days = (
            db.session.query(func.sum(T_user_point.point))
            .outerjoin(T_user_promotion_code, T_user_point.user_promotion_code_id == T_user_promotion_code.user_promotion_code_id)
            .outerjoin(M_promotion_code, T_user_promotion_code.promotion_code_id == M_promotion_code.promotion_code_id)
            .filter(
                T_user_point.user_id == userId,
                T_user_point.is_deleted == False,
                T_user_point.point is not None,
                or_(
                    M_promotion_code.valid_days.is_(None),
                    T_user_point.user_promotion_code_id.is_(None)
                )
            )
            .scalar() or 0
        )
        print("point_without_valid_days:", point_without_valid_days)
    except Exception as e:
        print("An error occurred while executing the query:", str(e))
        return 0

    point = point_with_valid_days + point_without_valid_days
    print('Points with valid dates:', point_with_valid_days)
    print('Points with no effective date:', point_without_valid_days)
    print('Total points:', point)
    return point

However, if the data something below

user_promotion_code_id
NULL
NULL
235
NULL

The following prints without any errors.

Subquery Acquisition Date:: anon_1.acquired_at
Subquery Points: anon_1.point
Subquery Effective Date: anon_1.valid_days
Subquery Results: [(datetime.datetime(2024, 4, 24, 3, 0), 10, 360)]
Expiration date 2025-04-19 03:00:00
point_with_valid_days 10
point_without_valid_days: 170
Points with valid dates: 10
Points with no effective date: 170
Total points: 180