pytest-mysql 2.5.0

Populating database for tests

With SQLAlchemy

This example shows how to populate database and create an SQLAlchemy’s ORM connection:

Sample below is simplified session fixture from pyramid_fullauth tests:

from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.pool import NullPool
from zope.sqlalchemy import register


@pytest.fixture
def db_session(mysql):
    """Session for SQLAlchemy."""
    from pyramid_fullauth.models import Base  # pylint:disable=import-outside-toplevel

    # assumes setting, these can be obtained from pytest-mysql config or mysql_proc
    connection = f'mysql+mysqldb://root:@127.0.0.1:3307/tests?charset=utf8'

    engine = create_engine(connection, echo=False, poolclass=NullPool)
    pyramid_basemodel.Session = scoped_session(sessionmaker(extension=ZopeTransactionExtension()))
    pyramid_basemodel.bind_engine(
        engine, pyramid_basemodel.Session, should_create=True, should_drop=True)

    yield pyramid_basemodel.Session

    transaction.commit()
    Base.metadata.drop_all(engine)


@pytest.fixture
def user(db_session):
    """Test user fixture."""
    from pyramid_fullauth.models import User
    from tests.tools import DEFAULT_USER

    new_user = User(**DEFAULT_USER)
    db_session.add(new_user)
    transaction.commit()
    return new_user


def test_remove_last_admin(db_session, user):
    """
    Sample test checks internal login, but shows usage in tests with SQLAlchemy
    """
    user = db_session.merge(user)
    user.is_admin = True
    transaction.commit()
    user = db_session.merge(user)

    with pytest.raises(AttributeError):
        user.is_admin = False

Connecting to MySQL/MariaDB (in a docker)

To connect to a docker run MySQL and run test on it, use noproc fixtures.

docker run --name some-db -e MYSQL_ALLOW_EMPTY_PASSWORD=yes -d mysql --expose 3306

docker run --name some-db -e MARIADB_ALLOW_EMPTY_PASSWORD=yes -d mariadb --expose 3306

This will start MySQL in a docker container, however using a MySQL installed locally is not much different.

In tests, make sure that all your tests are using mysql_noproc fixture like that:

mysql_in_docker = factories.mysql_noproc()
mysql = factories.mysql("mysql_in_docker")


def test_mysql_docker(mysql):
    """Run test."""
    cur = mysql.cursor()
    cur.query("CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20), species VARCHAR(20), sex CHAR(1), birth DATE, death DATE);")
    mysql.commit()
    cur.close()

And run tests:

pytest --mysql-host=127.0.0.1

Package resources

• Bug tracker: https://github.com/ClearcodeHQ/pytest-mysql/issues