import datetime import databases import ormar import sqlalchemy database = databases.Database("sqlite:///db.sqlite") metadata = sqlalchemy.MetaData() class Course(ormar.Model): ormar_config = ormar.OrmarConfig( database=database, metadata=metadata, # define your constraints in OrmarConfig of the model # it's a list that can contain multiple constraints # hera a combination of name and column will have a level check in the db constraints=[ ormar.CheckColumns("start_time < end_time", name="date_check"), ], ) id: int = ormar.Integer(primary_key=True) name: str = ormar.String(max_length=100) start_date: datetime.date = ormar.Date() end_date: datetime.date = ormar.Date()