Refs #27090 -- Added real database sequence introspection.

Thanks Mariusz Felisiak for the Oracle part and Tim Graham for the
review.

3 files changed, 55 insertions, 2 deletions

diff --git a/tests/backends/oracle/test_introspection.py b/tests/backends/oracle/test_introspection.py
new file mode 100644
index 0000000000..ac084e93df
--- /dev/null
+++ b/tests/backends/oracle/test_introspection.py
@@ -0,0 +1,29 @@
+import unittest
+
+from django.db import connection
+from django.test import TransactionTestCase
+
+from ..models import Person
+
+
+@unittest.skipUnless(connection.vendor == 'oracle', 'Oracle tests')
+class DatabaseSequenceTests(TransactionTestCase):
+    available_apps = []
+
+    def test_get_sequences(self):
+        with connection.cursor() as cursor:
+            seqs = connection.introspection.get_sequences(cursor, Person._meta.db_table, Person._meta.local_fields)
+            self.assertEqual(len(seqs), 1)
+            self.assertIsNotNone(seqs[0]['name'])
+            self.assertEqual(seqs[0]['table'], Person._meta.db_table)
+            self.assertEqual(seqs[0]['column'], 'id')
+
+    def test_get_sequences_manually_created_index(self):
+        with connection.cursor() as cursor:
+            with connection.schema_editor() as editor:
+                editor._drop_identity(Person._meta.db_table, 'id')
+                seqs = connection.introspection.get_sequences(cursor, Person._meta.db_table, Person._meta.local_fields)
+                self.assertEqual(seqs, [{'table': Person._meta.db_table, 'column': 'id'}])
+                # Recreate model, because adding identity is impossible.
+                editor.delete_model(Person)
+                editor.create_model(Person)
diff --git a/tests/backends/postgresql/test_introspection.py b/tests/backends/postgresql/test_introspection.py
new file mode 100644
index 0000000000..cfa801a77f
--- /dev/null
+++ b/tests/backends/postgresql/test_introspection.py
@@ -0,0 +1,23 @@
+import unittest
+
+from django.db import connection
+from django.test import TestCase
+
+from ..models import Person
+
+
+@unittest.skipUnless(connection.vendor == 'postgresql', "Test only for PostgreSQL")
+class DatabaseSequenceTests(TestCase):
+    def test_get_sequences(self):
+        cursor = connection.cursor()
+        seqs = connection.introspection.get_sequences(cursor, Person._meta.db_table)
+        self.assertEqual(
+            seqs,
+            [{'table': Person._meta.db_table, 'column': 'id', 'name': 'backends_person_id_seq'}]
+        )
+        cursor.execute('ALTER SEQUENCE backends_person_id_seq RENAME TO pers_seq')
+        seqs = connection.introspection.get_sequences(cursor, Person._meta.db_table)
+        self.assertEqual(
+            seqs,
+            [{'table': Person._meta.db_table, 'column': 'id', 'name': 'pers_seq'}]
+        )
diff --git a/tests/introspection/tests.py b/tests/introspection/tests.py
index c449b6de82..ed10927b2a 100644
--- a/tests/introspection/tests.py
+++ b/tests/introspection/tests.py
@@ -61,8 +61,9 @@ class IntrospectionTests(TransactionTestCase):
 
     def test_sequence_list(self):
         sequences = connection.introspection.sequence_list()
-        expected = {'table': Reporter._meta.db_table, 'column': 'id'}
-        self.assertIn(expected, sequences, 'Reporter sequence not found in sequence_list()')
+        reporter_seqs = [seq for seq in sequences if seq['table'] == Reporter._meta.db_table]
+        self.assertEqual(len(reporter_seqs), 1, 'Reporter sequence not found in sequence_list()')
+        self.assertEqual(reporter_seqs[0]['column'], 'id')
 
     def test_get_table_description_names(self):
         with connection.cursor() as cursor: