Fixed overridden functions not working with other DBs (#105)

Fixes issue #92 and other potential issues caused by overriding Django functions in functions.py.

Author: jmah8

mssql/functions.py

@@ -125,6 +125,13 @@ def sqlserver_orderby(self, compiler, connection):
 
 
 def split_parameter_list_as_sql(self, compiler, connection):
+    if connection.vendor == 'microsoft':
+        return mssql_split_parameter_list_as_sql(self, compiler, connection)
+    else:
+        return in_split_parameter_list_as_sql(self, compiler, connection)
+
+
+def mssql_split_parameter_list_as_sql(self, compiler, connection):
     # Insert In clause parameters 1000 at a time into a temp table.
     lhs, _ = self.process_lhs(compiler, connection)
     _, rhs_params = self.batch_process_rhs(compiler, connection)
@@ -215,10 +222,12 @@ def _get_check_sql(self, model, schema_editor):
     where = query.build_where(self.check)
     compiler = query.get_compiler(connection=schema_editor.connection)
     sql, params = where.as_sql(compiler, schema_editor.connection)
-    try:
-        for p in params: str(p).encode('ascii')
-    except UnicodeEncodeError:
-        sql = sql.replace('%s', 'N%s')
+    if schema_editor.connection.vendor == 'microsoft':
+        try:
+            for p in params:
+                str(p).encode('ascii')
+        except UnicodeEncodeError:
+            sql = sql.replace('%s', 'N%s')
 
     return sql % tuple(schema_editor.quote_value(p) for p in params)
 
@@ -264,7 +273,7 @@ def bulk_update_with_default(self, objs, fields, batch_size=None, default=0):
                         value_none_counter += 1
                     attr = Value(attr, output_field=field)
                 when_statements.append(When(pk=obj.pk, then=attr))
-            if(value_none_counter == len(when_statements)):
+            if connections[self.db].vendor == 'microsoft' and value_none_counter == len(when_statements):
                 case_statement = Case(*when_statements, output_field=field, default=Value(default))
             else:
                 case_statement = Case(*when_statements, output_field=field)
@@ -280,6 +289,8 @@ def bulk_update_with_default(self, objs, fields, batch_size=None, default=0):
 
 
 ATan2.as_microsoft = sqlserver_atan2
+# Need copy of old In.split_parameter_list_as_sql for other backends to call
+in_split_parameter_list_as_sql = In.split_parameter_list_as_sql
 In.split_parameter_list_as_sql = split_parameter_list_as_sql
 if VERSION >= (3, 1):
     KeyTransformIn.as_microsoft = json_KeyTransformIn

testapp/migrations/0017_binarydata_testcheckconstraintwithunicode_and_more.py

@@ -0,0 +1,39 @@
+# Generated by Django 4.0.2 on 2022-02-23 19:06
+
+from django import VERSION
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('testapp', '0016_jsonmodel'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='BinaryData',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('binary', models.BinaryField(max_length='max', null=True)),
+            ],
+        ),
+    ]
+
+    if VERSION >= (3, 2):
+        operations += [
+            migrations.CreateModel(
+                name='TestCheckConstraintWithUnicode',
+                fields=[
+                    ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                    ('name', models.CharField(max_length=100)),
+                ],
+                options={
+                    'required_db_features': {'supports_table_check_constraints'},
+                },
+            ),
+            migrations.AddConstraint(
+                model_name='testcheckconstraintwithunicode',
+                constraint=models.CheckConstraint(check=models.Q(('name__startswith', '÷'), _negated=True), name='name_does_not_starts_with_÷'),
+            ),
+        ]

testapp/models.py

@@ -154,9 +154,29 @@ class Meta:
     status = models.CharField(max_length=50)
 
 
+class BinaryData(models.Model):
+    binary = models.BinaryField(null=True)
+
+
 if VERSION >= (3, 1):
     class JSONModel(models.Model):
         value = models.JSONField()
 
         class Meta:
             required_db_features = {'supports_json_field'}
+
+
+if VERSION >= (3, 2):
+    class TestCheckConstraintWithUnicode(models.Model):
+        name = models.CharField(max_length=100)
+
+        class Meta:
+            required_db_features = {
+                'supports_table_check_constraints',
+            }
+            constraints = [
+                models.CheckConstraint(
+                    check=~models.Q(name__startswith='\u00f7'),
+                    name='name_does_not_starts_with_\u00f7',
+                )
+            ]

testapp/tests/test_multiple_databases.py

@@ -0,0 +1,96 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the BSD license.
+
+from unittest import skipUnless
+
+from django import VERSION
+from django.db import OperationalError
+from django.db.backends.sqlite3.operations import DatabaseOperations
+from django.test import TestCase, skipUnlessDBFeature
+
+from ..models import BinaryData, Pizza, Topping
+
+if VERSION >= (3, 2):
+    from ..models import TestCheckConstraintWithUnicode
+
+
+@skipUnless(
+    VERSION >= (3, 1),
+    "Django 3.0 and below doesn't support different databases in unit tests",
+)
+class TestMultpleDatabases(TestCase):
+    databases = ['default', 'sqlite']
+
+    def test_in_split_parameter_list_as_sql(self):
+        # Issue: https://github.com/microsoft/mssql-django/issues/92
+
+        # Mimic databases that have a limit on parameters (e.g. Oracle DB)
+        old_max_in_list_size = DatabaseOperations.max_in_list_size
+        DatabaseOperations.max_in_list_size = lambda self: 100
+
+        mssql_iterations = 3000
+        Pizza.objects.bulk_create([Pizza() for _ in range(mssql_iterations)])
+        Topping.objects.bulk_create([Topping() for _ in range(mssql_iterations)])
+        prefetch_result = Pizza.objects.prefetch_related('toppings')
+        self.assertEqual(len(prefetch_result), mssql_iterations)
+
+        # Different iterations since SQLite has max host parameters of 999 for versions prior to 3.32.0
+        # Info about limit: https://www.sqlite.org/limits.html
+        sqlite_iterations = 999
+        Pizza.objects.using('sqlite').bulk_create([Pizza() for _ in range(sqlite_iterations)])
+        Topping.objects.using('sqlite').bulk_create([Topping() for _ in range(sqlite_iterations)])
+        prefetch_result_sqlite = Pizza.objects.using('sqlite').prefetch_related('toppings')
+        self.assertEqual(len(prefetch_result_sqlite), sqlite_iterations)
+
+        DatabaseOperations.max_in_list_size = old_max_in_list_size
+
+    def test_binaryfield_init(self):
+        binary_data = b'\x00\x46\xFE'
+        binary = BinaryData(binary=binary_data)
+        binary.save()
+        binary.save(using='sqlite')
+
+        try:
+            binary.full_clean()
+        except ValidationError:
+            self.fail()
+
+        b1 = BinaryData.objects.filter(binary=binary_data)
+        self.assertSequenceEqual(
+            b1,
+            [binary],
+        )
+        b2 = BinaryData.objects.using('sqlite').filter(binary=binary_data)
+        self.assertSequenceEqual(
+            b2,
+            [binary],
+        )
+
+    @skipUnlessDBFeature('supports_table_check_constraints')
+    @skipUnless(
+        VERSION >= (3, 2),
+        "Django 3.1 and below has errors from running migrations for this test",
+    )
+    def test_checkconstraint_get_check_sql(self):
+        TestCheckConstraintWithUnicode.objects.create(name='abc')
+        try:
+            TestCheckConstraintWithUnicode.objects.using('sqlite').create(name='abc')
+        except OperationalError:
+            self.fail()
+
+    def test_queryset_bulk_update(self):
+        objs = [
+            BinaryData.objects.create(binary=b'\x00') for _ in range(5)
+        ]
+        for obj in objs:
+            obj.binary = None
+        BinaryData.objects.bulk_update(objs, ["binary"])
+        self.assertCountEqual(BinaryData.objects.filter(binary__isnull=True), objs)
+
+        objs = [
+            BinaryData.objects.using('sqlite').create(binary=b'\x00') for _ in range(5)
+        ]
+        for obj in objs:
+            obj.binary = None
+        BinaryData.objects.using('sqlite').bulk_update(objs, ["binary"])
+        self.assertCountEqual(BinaryData.objects.using('sqlite').filter(binary__isnull=True), objs)