how can i define a column as a positive integer using flask sqlalchemy? i am hoping the answer would look something like this: class City(db.Model): id = db.Column(db.Integer, primary_key=True) population = db.Column(db.Integer, positive=True) def __init__(self,population): self.population = population however, this class definition will throw an error b/c sqlalchemy does not know about a 'positive' argument. i could raise an exception if an object is instantiated with a negative value for the population. but i don't know how to ensure that the population remains positive after an update. thanks for any help. Continue reading...
