Instantiating Fixtures¶

For for the following examples, assume this fixture

class ArnoldPerson(BaseFix):
    MODEL = Person

    first_name = "Arnold"
    family_name = "Schwarz"

First you need to instantiate the fixture class and pass the SqlaFixFact instance as fist parameter:

fixture = ArnoldPerson(fix_fact)

You can add additional kwargs to alter the default values. For more details see Substitution of Values

To get a SQLAlchemy ORM model instance there are 3 ways

create()¶

Adds this model to the session. This instance is not registered and thus can never be referred to via BaseFix.get(). Thus each call to create() adds a new instance of the fixture to the DB.

arnold_fix_1 = ArnoldPerson(fix_fact).create()
arnold_fix_2 = ArnoldPerson(fix_fact).create()
arnold_fix_3 = ArnoldPerson(fix_fact).create()

db_session.query(Person).count()  # is 3

get()¶

Returns an already existing model instance, or creates one and registers it to be able to find it later and then returns the instance.

Note: Changed properties via the kwargs parameter are recognized and result in a new instance.

arnold_fix_1 = ArnoldPerson(fix_fact).get()
arnold_fix_2 = ArnoldPerson(fix_fact).get()
arnold_fix_3 = ArnoldPerson(fix_fact).get()

db_session.query(Person).count()  # is 1

model()¶

Returns a model instance of this fixture which is ready to be added. The model itself is not added to the DB but all dependencies are.

arnold_fix = ArnoldPerson(fix_fact).model()

db_session.query(Person).count()  # is 0

db_session.add(arnold_fix)
db_session.query(Person).count()  # is 1