CODEWITHSUNDEEP
pythonpython-2.7sqlalchemyflask-sqlalchemy
rockets4all
rockets4all

Reputation: 886

sqlalchemy make columns follow relationship with rules

How do I get attr to be the name of the column being checked and value the value of the column being checked?

models.py

class Dates(db.Model):
    username=db.Column(db.String, primary_key=True)
    apples = db.Column(db.DateTime)
    oranges = db.Column(db.DateTime)
    milk = db.Column(db.DateTime)
    bananas = db.Column(db.DateTime)
    beans = db.Column(db.DateTime)

    def is_expired(self, date)
        #I want attr to equal the column it is coming from
        #example if I typed Dates.apples.is_expired('2017-01-01')
        #I want attr to equal 'apples', that way Rules.rule brings back
        # the rule # associated with apples
        #I want value to be the date from Dates.apples
        a=Rules.query.filter_by(name=attr).first()
        if a.rule=='1':
            value=datetime.datetime.strptime(value, '%Y-%m-%d')
            date=datetime.datetime.strptime(date, '%Y-%m-%d')
            for i in range(36):
                value=add_one_month(value)
            if date>value:
                return True
            else:
                return False
        elif a.rule=='2':
            value=datetime.datetime.strptime(value, '%Y-%m-%d')
            date=datetime.datetime.strptime(date, '%Y-%m-%d')
            for i in range(12):
                value=add_one_month(value)
            if date>value:
                return True
            else:
                return False

    def __repr__(self):  # pragma: no cover
        return '<Mobility %r>' % (self.username)

class Rules(db.model)
    rule=db.Column(db.Integer, primary_key=True)
    name=db.Column(db.String(45))

    def __repr__(self):  # pragma: no cover
        return '<Mobility %r>' % (self.name)

Example of a call in another function:

user=Dates.query.filter_by(username='bob').first()
user.apples='2017-02-11'
if user.apples.is_expired('2017-04-12'):
    color=red

In this case attr='apples', value='2017=02-11'

Upvotes: 1

Views: 150

Answers (1)

Borys Serebrov
Borys Serebrov

Reputation: 16182

If you want to have attr inside the function, you should pass it as a parameter. This is not about SQLAlchemy actually - python object don't work the way you try to use it here: object.attr.method() is not a valid way to call object's method.

Instead you need something like user.is_expired('apples', '2017-04-12'). Inside the method you can get the field value as getattr(self, attr_name), assuming that you change the method signature to def is_expired(self, attr_name, date).

Upvotes: 1

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