from sqlalchemy.dialects.postgresql import ranges, ExcludeConstraint

class Quarter(db.Model):
    __tablename__ = 'quarters'

    id = db.Column(db.Integer, primary_key=True)
    year = db.Column(db.Integer, nullable=False)
    name = db.Column(db.Text, nullable=False)
    period = db.Column(ranges.DATERANGE, nullable=False)