Fixed #30510 -- Fixed crash of QuerySet.bulk_create() with mixed-length texts on Oracle.

Text with more than 4000 characters must be set to as a CLOB on Oracle
what caused a mixed datatype error (ORA-01790) when shorter text
appeared in the same operation.

django/db/backends/oracle/utils.py

@@ -54,6 +54,7 @@ class Oracle_datetime(datetime.datetime):
 
 class BulkInsertMapper:
     BLOB = 'TO_BLOB(%s)'
+    CBLOB = 'TO_CLOB(%s)'
     DATE = 'TO_DATE(%s)'
     INTERVAL = 'CAST(%s as INTERVAL DAY(9) TO SECOND(6))'
     NUMBER = 'TO_NUMBER(%s)'
@@ -73,5 +74,6 @@ class BulkInsertMapper:
         'PositiveIntegerField': NUMBER,
         'PositiveSmallIntegerField': NUMBER,
         'SmallIntegerField': NUMBER,
+        'TextField': CBLOB,
         'TimeField': TIMESTAMP,
     }

tests/bulk_create/tests.py

@@ -49,6 +49,16 @@ class BulkCreateTests(TestCase):
         Country.objects.bulk_create([Country(description='Ж' * 3000)])
         self.assertEqual(Country.objects.count(), 1)
 
+    @skipUnlessDBFeature('has_bulk_insert')
+    def test_long_and_short_text(self):
+        Country.objects.bulk_create([
+            Country(description='a' * 4001),
+            Country(description='a'),
+            Country(description='Ж' * 2001),
+            Country(description='Ж'),
+        ])
+        self.assertEqual(Country.objects.count(), 4)
+
     def test_multi_table_inheritance_unsupported(self):
         expected_message = "Can't bulk create a multi-table inherited model"
         with self.assertRaisesMessage(ValueError, expected_message):