[1.11.x] Refs #18247 -- Fixed SQLite QuerySet filtering on decimal result of Least and Greatest.

Backport of 068d75688f from master

django/db/models/expressions.py

@@ -570,8 +570,8 @@ class Func(Expression):
         data['expressions'] = data['field'] = arg_joiner.join(sql_parts)
         return template % data, params
 
-    def as_sqlite(self, compiler, connection):
-        sql, params = self.as_sql(compiler, connection)
+    def as_sqlite(self, compiler, connection, **extra_context):
+        sql, params = self.as_sql(compiler, connection, **extra_context)
         try:
             if self.output_field.get_internal_type() == 'DecimalField':
                 sql = 'CAST(%s AS NUMERIC)' % sql

django/db/models/functions/base.py

@@ -137,7 +137,7 @@ class Greatest(Func):
 
     def as_sqlite(self, compiler, connection):
         """Use the MAX function on SQLite."""
-        return super(Greatest, self).as_sql(compiler, connection, function='MAX')
+        return super(Greatest, self).as_sqlite(compiler, connection, function='MAX')
 
 
 class Least(Func):
@@ -157,7 +157,7 @@ class Least(Func):
 
     def as_sqlite(self, compiler, connection):
         """Use the MIN function on SQLite."""
-        return super(Least, self).as_sql(compiler, connection, function='MIN')
+        return super(Least, self).as_sqlite(compiler, connection, function='MIN')
 
 
 class Length(Transform):

tests/db_functions/models.py

@@ -56,3 +56,8 @@ class DTModel(models.Model):
 
     def __str__(self):
         return 'DTModel({0})'.format(self.name)
+
+
+class DecimalModel(models.Model):
+    n1 = models.DecimalField(decimal_places=2, max_digits=6)
+    n2 = models.DecimalField(decimal_places=2, max_digits=6)

tests/db_functions/tests.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 from datetime import datetime, timedelta
+from decimal import Decimal
 from unittest import skipIf, skipUnless
 
 from django.db import connection
@@ -13,7 +14,7 @@ from django.db.models.functions import (
 from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
 from django.utils import timezone
 
-from .models import Article, Author, Fan
+from .models import Article, Author, DecimalModel, Fan
 
 
 lorem_ipsum = """
@@ -204,6 +205,15 @@ class FunctionTests(TestCase):
         author.refresh_from_db()
         self.assertEqual(author.alias, 'Jim')
 
+    def test_greatest_decimal_filter(self):
+        obj = DecimalModel.objects.create(n1=Decimal('1.1'), n2=Decimal('1.2'))
+        self.assertCountEqual(
+            DecimalModel.objects.annotate(
+                greatest=Greatest('n1', 'n2'),
+            ).filter(greatest=Decimal('1.2')),
+            [obj],
+        )
+
     def test_least(self):
         now = timezone.now()
         before = now - timedelta(hours=1)
@@ -299,6 +309,15 @@ class FunctionTests(TestCase):
         author.refresh_from_db()
         self.assertEqual(author.alias, 'James Smith')
 
+    def test_least_decimal_filter(self):
+        obj = DecimalModel.objects.create(n1=Decimal('1.1'), n2=Decimal('1.2'))
+        self.assertCountEqual(
+            DecimalModel.objects.annotate(
+                least=Least('n1', 'n2'),
+            ).filter(least=Decimal('1.1')),
+            [obj],
+        )
+
     def test_concat(self):
         Author.objects.create(name='Jayden')
         Author.objects.create(name='John Smith', alias='smithj', goes_by='John')