class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
age = Column(Integer)# i need age to have mix value of 0 and max of 100
email = Column(String)
sqlalchemy documentation says that there no such atributes to pass while creating a column
This is probably because none of the RDBMSes I'm familiar with support min/max in the column definition.
If you need to enforce that you can write a trigger or if your DB supports it you can add a check constraint.
https://dev.mysql.com/blog-archive/mysql-8-0-16-introducing-check-constraint/
As described in brunson's answer, you can add a check constraint to perform the validation in the database, if the database supports check constraints.
import sqlalchemy as sa
...
class Test(Base):
__tablename__ = 'test'
id = sa.Column(sa.Integer, primary_key=True)
age = sa.Column(sa.Integer, sa.CheckConstraint('age > 0 AND age < 100'))
It may be more convenient to perform the validation before data is sent to the database, in the application layer. In this case, the orm.validates decorator can be used:
class Test(Base):
__tablename__ = 'test'
id = sa.Column(sa.Integer, primary_key=True)
age = sa.Column(sa.Integer, sa.CheckConstraint('age > 0 AND age < 100'))
@orm.validates('age')
def validate_age(self, key, value):
if not 0 < value < 100:
raise ValueError(f'Invalid age {value}')