Flask SQLAlchemy filter by value OR another

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隐瞒了意图╮
隐瞒了意图╮ 2021-01-31 11:29

I have a Flask project that interacts with MySQL db through Flask-SQLAlchemy.

My question is, how to select a row from the database based on a v

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  •  后悔当初
    2021-01-31 12:24

    The following may help:

    # app.py
    from flask import Flask
    from flask_sqlalchemy import SQLAlchemy
    
    app = Flask(__name__)
    app.config['SQLALCHEMY_DATABASE_URI'] = 'url_or_path/to/database'
    db = SQLAlchemy(app)
    
    class User(db.Model):
        __tablename__ = 'users'
        id = db.Column(db.Integer, primary_key=True)
        email = db.Column(db.String(50), unique=True)
        name = db.Column(db.String(30))
    
        def __init__(self, name=None, email=None):
            if not name:
                raise ValueError('\'name\' cannot be None')
            if not email:
                raise ValueError('\'email\' cannot be None')
            self.name = name
            self.email = email
    
    class UserQuery(object):
        @staticmethod
        def get_user_id_by_email_or_name(email=None, name=None):
            user = User.query.filter((User.email == email) | (User.name == name)).first()
            return user.id if hasattr(user, 'id') else None
    

    The '|' can be used inside a filter instead of 'or_'. See Using OR in SQLAlchemy.

    You can use like this:

    >>> from app import db, User, UserQuery
    >>> db.create_all()
    >>> user = User(name='stan', email='stan@email.com')
    >>> db.session.add(user)
    >>> db.session.commit()
    >>> by_name_id = UserQuery.get_user_id_by_email_or_name(name='stan')
    >>> by_email_id = UserQuery.get_user_id_by_email_or_name(email='stan@email.com')
    >>> by_name_id == by_email_id
    True
    

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