models/setting.py

from database import db


class Setting(db.Model):
    __tablename__ = "settings"

    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
    key = db.Column(db.String(100), nullable=False)
    value = db.Column(db.Text, nullable=True)

    __table_args__ = (db.UniqueConstraint("user_id", "key"),)

    def to_dict(self):
        return {"key": self.key, "value": self.value}