本文整理匯總了Python中django.db.migrations.AddConstraint方法的典型用法代碼示例。如果您正苦於以下問題：Python migrations.AddConstraint方法的具體用法？Python migrations.AddConstraint怎麽用？Python migrations.AddConstraint使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類django.db.migrations的用法示例。
在下文中一共展示了migrations.AddConstraint方法的2個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Python代碼示例。
示例1: test_add_constraint
# 需要導入模塊: from django.db import migrations [as 別名]
# 或者: from django.db.migrations import AddConstraint [as 別名]
def test_add_constraint(self):
project_state = self.set_up_test_model("test_addconstraint")
gt_check = models.Q(pink__gt=2)
gt_constraint = models.CheckConstraint(check=gt_check, name="test_add_constraint_pony_pink_gt_2")
gt_operation = migrations.AddConstraint("Pony", gt_constraint)
self.assertEqual(
gt_operation.describe(), "Create constraint test_add_constraint_pony_pink_gt_2 on model Pony"
)
# Test the state alteration
new_state = project_state.clone()
gt_operation.state_forwards("test_addconstraint", new_state)
self.assertEqual(len(new_state.models["test_addconstraint", "pony"].options["constraints"]), 1)
Pony = new_state.apps.get_model("test_addconstraint", "Pony")
self.assertEqual(len(Pony._meta.constraints), 1)
# Test the database alteration
with connection.schema_editor() as editor:
gt_operation.database_forwards("test_addconstraint", editor, project_state, new_state)
with self.assertRaises(IntegrityError), transaction.atomic():
Pony.objects.create(pink=1, weight=1.0)
# Add another one.
lt_check = models.Q(pink__lt=100)
lt_constraint = models.CheckConstraint(check=lt_check, name="test_add_constraint_pony_pink_lt_100")
lt_operation = migrations.AddConstraint("Pony", lt_constraint)
lt_operation.state_forwards("test_addconstraint", new_state)
self.assertEqual(len(new_state.models["test_addconstraint", "pony"].options["constraints"]), 2)
Pony = new_state.apps.get_model("test_addconstraint", "Pony")
self.assertEqual(len(Pony._meta.constraints), 2)
with connection.schema_editor() as editor:
lt_operation.database_forwards("test_addconstraint", editor, project_state, new_state)
with self.assertRaises(IntegrityError), transaction.atomic():
Pony.objects.create(pink=100, weight=1.0)
# Test reversal
with connection.schema_editor() as editor:
gt_operation.database_backwards("test_addconstraint", editor, new_state, project_state)
Pony.objects.create(pink=1, weight=1.0)
# Test deconstruction
definition = gt_operation.deconstruct()
self.assertEqual(definition[0], "AddConstraint")
self.assertEqual(definition[1], [])
self.assertEqual(definition[2], {'model_name': "Pony", 'constraint': gt_constraint}) 示例2: test_add_partial_unique_constraint
# 需要導入模塊: from django.db import migrations [as 別名]
# 或者: from django.db.migrations import AddConstraint [as 別名]
def test_add_partial_unique_constraint(self):
project_state = self.set_up_test_model('test_addpartialuniqueconstraint')
partial_unique_constraint = models.UniqueConstraint(
fields=['pink'],
condition=models.Q(weight__gt=5),
name='test_constraint_pony_pink_for_weight_gt_5_uniq',
)
operation = migrations.AddConstraint('Pony', partial_unique_constraint)
self.assertEqual(
operation.describe(),
'Create constraint test_constraint_pony_pink_for_weight_gt_5_uniq '
'on model Pony'
)
# Test the state alteration
new_state = project_state.clone()
operation.state_forwards('test_addpartialuniqueconstraint', new_state)
self.assertEqual(len(new_state.models['test_addpartialuniqueconstraint', 'pony'].options['constraints']), 1)
Pony = new_state.apps.get_model('test_addpartialuniqueconstraint', 'Pony')
self.assertEqual(len(Pony._meta.constraints), 1)
# Test the database alteration
with connection.schema_editor() as editor:
operation.database_forwards('test_addpartialuniqueconstraint', editor, project_state, new_state)
# Test constraint works
Pony.objects.create(pink=1, weight=4.0)
Pony.objects.create(pink=1, weight=4.0)
Pony.objects.create(pink=1, weight=6.0)
if connection.features.supports_partial_indexes:
with self.assertRaises(IntegrityError), transaction.atomic():
Pony.objects.create(pink=1, weight=7.0)
else:
Pony.objects.create(pink=1, weight=7.0)
# Test reversal
with connection.schema_editor() as editor:
operation.database_backwards('test_addpartialuniqueconstraint', editor, new_state, project_state)
# Test constraint doesn't work
Pony.objects.create(pink=1, weight=7.0)
# Test deconstruction
definition = operation.deconstruct()
self.assertEqual(definition[0], 'AddConstraint')
self.assertEqual(definition[1], [])
self.assertEqual(definition[2], {'model_name': 'Pony', 'constraint': partial_unique_constraint})