CODEWITHSUNDEEP
pythonsqlalchemy
RyanTheRyan
RyanTheRyan

Reputation: 83

TypeError: int() argument must be a string, a bytes-like object or a number, not 'result'

I'm trying to take the highest id and add one to make a new id. When I try to start it (it's at null as nothing is in there yet) it gives me this error: TypeError: int() argument must be a string, a bytes-like object or a number, not 'result'.

@app.route('/new-recipe', methods=['POST'])
def create_recipe(application):
    data = request.get_json()
    current_id = int(db.session.query(func.max(Recipes.id)).first())
    # I've tried without int() too.

    if current_id >= 1:
        new_id = current_id + 1
        new_recipe = Recipes(id=new_id)
        return new_recipe.id
    else:
        new_recipe = Recipes(id=1)
        return new_recipe.id

Upvotes: 0

Views: 726

Answers (1)

JanLikar
JanLikar

Reputation: 1306

You can use .scalar() to convert from a result to a value.

current_id = db.session.query(func.max(Recipes.id)).scalar()

See https://docs.sqlalchemy.org/en/13/orm/query.html#sqlalchemy.orm.query.Query.scalar

I do, however, have a comment on your approach: it would be better to let the database generate the ids for you, because code like yours could behave unpredictably when multiple people are accessing /new-recipe at the same time.

If you get the last id and then do an insert in a separate query (while not in a database transaction), someone else can insert a record with the same ID, as the one you're attempting to insert, before you. This would cause an error.

Upvotes: 2

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