Fixed #27219 -- Changed cx_Oracle client encoding to AL32UTF8 to allow 4-byte characters.

django/db/backends/oracle/base.py

@@ -41,7 +41,7 @@ def _setup_environment(environ):
 
 _setup_environment([
     # Oracle takes client-side character set encoding from the environment.
-    ('NLS_LANG', '.UTF8'),
+    ('NLS_LANG', '.AL32UTF8'),
     # This prevents unicode from getting mangled by getting encoded into the
     # potentially non-unicode database character set.
     ('ORA_NCHAR_LITERAL_REPLACE', 'TRUE'),

tests/model_fields/test_charfield.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from unittest import skipIf
+
 from django.core.exceptions import ValidationError
-from django.db import models
+from django.db import connection, models
 from django.test import SimpleTestCase, TestCase
 from django.utils.functional import lazy
 
@@ -21,6 +26,12 @@ class TestCharField(TestCase):
     def test_lookup_integer_in_charfield(self):
         self.assertEqual(Post.objects.filter(title=9).count(), 0)
 
+    @skipIf(connection.vendor == 'mysql', 'See https://code.djangoproject.com/ticket/18392')
+    def test_emoji(self):
+        p = Post.objects.create(title='Smile 😀', body='Whatever.')
+        p.refresh_from_db()
+        self.assertEqual(p.title, 'Smile 😀')
+
 
 class ValidationTests(SimpleTestCase):
 

tests/model_fields/test_textfield.py

-from django.db import models
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from unittest import skipIf
+
+from django.db import connection, models
 from django.test import TestCase
 
 from .models import Post
@@ -23,3 +28,9 @@ class TextFieldTests(TestCase):
 
     def test_lookup_integer_in_textfield(self):
         self.assertEqual(Post.objects.filter(body=24).count(), 0)
+
+    @skipIf(connection.vendor == 'mysql', 'See https://code.djangoproject.com/ticket/18392')
+    def test_emoji(self):
+        p = Post.objects.create(title='Whatever', body='Smile 😀.')
+        p.refresh_from_db()
+        self.assertEqual(p.body, 'Smile 😀.')