def test_schema_editor_create_delete_materialized_view():
"""Tests whether creating and then deleting a materialized view using the
schema editor works as expected."""
underlying_model = get_fake_model({"name": models.TextField()})
model = define_fake_materialized_view_model(
{"name": models.TextField()},
{"query": underlying_model.objects.filter(name="test1")},
)
underlying_model.objects.create(name="test1")
underlying_model.objects.create(name="test2")
schema_editor = PostgresSchemaEditor(connection)
schema_editor.create_materialized_view_model(model)
# materialized view should only show records name="test"1
objs = list(model.objects.all())
assert len(objs) == 1
assert objs[0].name == "test1"
# delete the materialized view
schema_editor.delete_materialized_view_model(model)
# make sure it was actually deleted
assert model._meta.db_table not in db_introspection.table_names(True)
def test_materialized_view_model_refresh():
"""Tests whether a materialized view can be refreshed."""
underlying_model = get_fake_model({"name": models.TextField()})
model = define_fake_materialized_view_model(
{"name": models.TextField()},
{"query": underlying_model.objects.filter(name="test1")},
)
underlying_model.objects.create(name="test1")
underlying_model.objects.create(name="test2")
schema_editor = PostgresSchemaEditor(connection)
schema_editor.create_materialized_view_model(model)
# materialized view should only show records name="test"1
objs = list(model.objects.all())
assert len(objs) == 1
assert objs[0].name == "test1"
# create another record with "test1" and refresh
underlying_model.objects.create(name="test1")
model.refresh()
objs = list(model.objects.all())
assert len(objs) == 2
def test_schema_editor_replace_materialized_view():
"""Tests whether creating a materialized view and then replacing it with
another one (thus changing the backing query) works as expected."""
underlying_model = get_fake_model({"name": models.TextField()})
model = define_fake_materialized_view_model(
{"name": models.TextField()},
{"query": underlying_model.objects.filter(name="test1")},
{"indexes": [models.Index(fields=["name"])]},
)
underlying_model.objects.create(name="test1")
underlying_model.objects.create(name="test2")
schema_editor = PostgresSchemaEditor(connection)
schema_editor.create_materialized_view_model(model)
for index in model._meta.indexes:
schema_editor.add_index(model, index)
constraints_before = db_introspection.get_constraints(model._meta.db_table)
objs = list(model.objects.all())
assert len(objs) == 1
assert objs[0].name == "test1"
model._view_meta.query = underlying_model.objects.filter(
name="test2"
).query.sql_with_params()
schema_editor.replace_materialized_view_model(model)
objs = list(model.objects.all())
assert len(objs) == 1
assert objs[0].name == "test2"
# make sure all indexes/constraints still exists because
# replacing a materialized view involves re-creating it
constraints_after = db_introspection.get_constraints(model._meta.db_table)
assert constraints_after == constraints_before
