Declaring Models

Declaring models

You can define models by inheriting from orm.Model and defining model fields in the fields attribute. For each defined model you need to set two special variables:

• registry an instance of orm.ModelRegistry
• fields a dict of orm fields

You can also specify the table name in database by setting tablename attribute.

import databases
import orm

database = databases.Database("sqlite:///db.sqlite")
models = orm.ModelRegistry(database=database)


class Note(orm.Model):
    tablename = "notes"
    registry = models
    fields = {
        "id": orm.Integer(primary_key=True),
        "text": orm.String(max_length=100),
        "completed": orm.Boolean(default=False),
    }

ORM can create or drop database and tables from models using SQLAlchemy. You can use the following methods:

await models.create_all()

await models.drop_all()

Data types

The following keyword arguments are supported on all field types.

• primary_key - A boolean. Determine if column is primary key.
• allow_null - A boolean. Determine if column is nullable.
• default - A value or a callable (function).
• index - A boolean. Determine if database indexes should be created.
• unique - A boolean. Determine if unique constraint should be created.

All fields are required unless one of the following is set:

• allow_null - A boolean. Determine if column is nullable. Sets the default to None.
• allow_blank - A boolean. Determine if empty strings are allowed. Sets the default to "".
• default - A value or a callable (function).

The following column types are supported. See TypeSystem for type-specific validation keyword arguments.

• orm.BigInteger()
• orm.Boolean()
• orm.Date()
• orm.DateTime()
• orm.Decimal()
• orm.Email(max_length)
• orm.Enum()
• orm.Float()
• orm.Integer()
• orm.IPAddress()
• orm.String(max_length)
• orm.Text()
• orm.Time()
• orm.URL(max_length)
• orm.UUID()
• orm.JSON()