PostgreSQL

The PostgreSQL adapter uses (SQLAlchemy)[https://www.sqlalchemy.org/] under the covers as the ORM to communicate with the database.

Configuration

[databases.default]
provider = "postgresql"
database_uri = "postgresql://postgres:postgres@localhost:5432/postgres"

Options

provider

postgresql is the provider for PostgreSQL.

database_uri

Connection string that specifies how to connect to a PostgreSQL database.

schema

Specifies the database schema to use in the database.

SQLAlchemy Model

You can supply a custom SQLAlchemy Model in place of the one that Protean generates internally, allowing you full customization.

import sqlalchemy as sa

from protean import Domain
from protean.adapters.repository.sqlalchemy import SqlalchemyModel
from protean.fields import Integer, String

domain = Domain(__file__)
domain.config["databases"]["default"] = {
    "provider": "postgresql",
    "database_uri": "postgresql://postgres:postgres@localhost:5432/postgres",
}


@domain.aggregate
class Provider:
    name = String()
    age = Integer()


@domain.model(part_of=Provider)
class ProviderCustomModel:
    name = sa.Column(sa.Text)
    age = sa.Column(sa.Integer)


domain.init()
with domain.domain_context():
    model_cls = domain.repository_for(Provider)._model
    assert issubclass(model_cls, SqlalchemyModel)

Note

The column names specified in the model should exactly match the attribute names of the Aggregate or Entity it represents.