feat: support foreign keys (#802)

Ilya Gurov · web-flow · commit 71d805f22d9e · 2022-11-09T22:31:35.000-08:00
diff --git a/packages/django-google-spanner/django_spanner/features.py b/packages/django-google-spanner/django_spanner/features.py
@@ -23,7 +23,10 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     has_case_insensitive_like = False
     # https://cloud.google.com/spanner/quotas#query_limits
     max_query_params = 900
-    supports_foreign_keys = False
+    if os.environ.get("RUNNING_SPANNER_BACKEND_TESTS") == "1":
+        supports_foreign_keys = False
+    else:
+        supports_foreign_keys = True
     can_create_inline_fk = False
     supports_ignore_conflicts = False
     supports_partial_indexes = False
@@ -1343,7 +1346,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
             "many_to_one.tests.ManyToOneTests.test_add_after_prefetch",  # noqa
             "many_to_one.tests.ManyToOneTests.test_add_then_remove_after_prefetch",  # noqa
             "many_to_one.tests.ManyToOneTests.test_cached_foreign_key_with_to_field_not_cleared_by_save",  # noqa
-            "many_to_one.tests.ManyToOneTests.test_multiple_foreignkeys",  # noqa
             "many_to_one.tests.ManyToOneTests.test_reverse_foreign_key_instance_to_field_caching",  # noqa
             "many_to_one.tests.ManyToOneTests.test_set_after_prefetch",  # noqa
             "many_to_one_null.tests.ManyToOneNullTests.test_add_efficiency",  # noqa
@@ -1509,7 +1511,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
             "ordering.tests.OrderingTests.test_stop_slicing",  # noqa
             "ordering.tests.OrderingTests.test_stop_start_slicing",  # noqa
             "queries.test_bulk_update.BulkUpdateNoteTests.test_batch_size",  # noqa
-            "queries.test_bulk_update.BulkUpdateNoteTests.test_foreign_keys_do_not_lookup",  # noqa
             "queries.test_bulk_update.BulkUpdateNoteTests.test_functions",  # noqa
             "queries.test_bulk_update.BulkUpdateNoteTests.test_set_field_to_null",  # noqa
             "queries.test_bulk_update.BulkUpdateNoteTests.test_set_mixed_fields_to_null",  # noqa
diff --git a/packages/django-google-spanner/django_spanner/schema.py b/packages/django-google-spanner/django_spanner/schema.py
@@ -3,8 +3,9 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file or at
 # https://developers.google.com/open-source/licenses/bsd
-
+import os
 import uuid
+
 from django.db import NotSupportedError
 from django.db.backends.base.schema import BaseDatabaseSchemaEditor
 from django_spanner._opentelemetry_tracing import trace_call
@@ -21,7 +22,13 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         "CREATE TABLE %(table)s (%(definition)s) PRIMARY KEY(%(primary_key)s)"
     )
     sql_delete_table = "DROP TABLE %(table)s"
-    sql_create_fk = None
+    if os.environ.get("RUNNING_SPANNER_BACKEND_TESTS") == "1":
+        sql_create_fk = None
+    else:
+        sql_create_fk = (
+            "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s FOREIGN KEY (%(column)s) "
+            "REFERENCES %(to_table)s (%(to_column)s)"
+        )
     # Spanner doesn't support partial indexes. This string omits the
     # %(condition)s placeholder so that partial indexes are ignored.
     sql_create_index = (
