Fixed #11863: added a Model.objects.raw() method for executing raw SQL queries and yield models.

See `docs/topics/db/raw.txt` for details.

Thanks to seanoc for getting the ball rolling, and to Russ for wrapping things up.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11921 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/modeltests/raw_query/tests.py

@@ -0,0 +1,188 @@
+from django.test import TestCase
+from datetime import datetime
+from models import Author, Book, Coffee, Reviewer
+from django.db.models.sql.query import InvalidQuery
+
+class RawQueryTests(TestCase):
+
+    def assertSuccessfulRawQuery(self, model, query, expected_results,
+            expected_annotations=(), params=[], translations=None):
+        """
+        Execute the passed query against the passed model and check the output
+        """
+        results = list(model.objects.raw(query=query, params=params, translations=translations))
+        self.assertProcessed(results, expected_results, expected_annotations)
+        self.assertAnnotations(results, expected_annotations)
+
+    def assertProcessed(self, results, orig, expected_annotations=()):
+        """
+        Compare the results of a raw query against expected results
+        """
+        self.assertEqual(len(results), len(orig))
+        for index, item in enumerate(results):
+            orig_item = orig[index]
+            for annotation in expected_annotations:
+                setattr(orig_item, *annotation)
+
+            self.assertEqual(item.id, orig_item.id)
+
+    def assertNoAnnotations(self, results):
+        """
+        Check that the results of a raw query contain no annotations
+        """
+        self.assertAnnotations(results, ())
+
+    def assertAnnotations(self, results, expected_annotations):
+        """
+        Check that the passed raw query results contain the expected
+        annotations
+        """
+        if expected_annotations:
+            for index, result in enumerate(results):
+                annotation, value = expected_annotations[index]
+                self.assertTrue(hasattr(result, annotation))
+                self.assertEqual(getattr(result, annotation), value)
+
+    def testSimpleRawQuery(self):
+        """
+        Basic test of raw query with a simple database query
+        """
+        query = "SELECT * FROM raw_query_author"
+        authors = Author.objects.all()
+        self.assertSuccessfulRawQuery(Author, query, authors)
+
+    def testRawQueryLazy(self):
+        """
+        Raw queries are lazy: they aren't actually executed until they're
+        iterated over.
+        """
+        q = Author.objects.raw('SELECT * FROM raw_query_author')
+        self.assert_(q.query.cursor is None)
+        list(q)
+        self.assert_(q.query.cursor is not None)
+
+    def testFkeyRawQuery(self):
+        """
+        Test of a simple raw query against a model containing a foreign key
+        """
+        query = "SELECT * FROM raw_query_book"
+        books = Book.objects.all()
+        self.assertSuccessfulRawQuery(Book, query, books)
+
+    def testDBColumnHandler(self):
+        """
+        Test of a simple raw query against a model containing a field with
+        db_column defined.
+        """
+        query = "SELECT * FROM raw_query_coffee"
+        coffees = Coffee.objects.all()
+        self.assertSuccessfulRawQuery(Coffee, query, coffees)
+
+    def testOrderHandler(self):
+        """
+        Test of raw raw query's tolerance for columns being returned in any
+        order
+        """
+        selects = (
+            ('dob, last_name, first_name, id'),
+            ('last_name, dob, first_name, id'),
+            ('first_name, last_name, dob, id'),
+        )
+
+        for select in selects:
+            query = "SELECT %s FROM raw_query_author" % select
+            authors = Author.objects.all()
+            self.assertSuccessfulRawQuery(Author, query, authors)
+
+    def testTranslations(self):
+        """
+        Test of raw query's optional ability to translate unexpected result
+        column names to specific model fields
+        """
+        query = "SELECT first_name AS first, last_name AS last, dob, id FROM raw_query_author"
+        translations = {'first': 'first_name', 'last': 'last_name'}
+        authors = Author.objects.all()
+        self.assertSuccessfulRawQuery(Author, query, authors, translations=translations)
+
+    def testParams(self):
+        """
+        Test passing optional query parameters
+        """
+        query = "SELECT * FROM raw_query_author WHERE first_name = %s"
+        author = Author.objects.all()[2]
+        params = [author.first_name]
+        results = list(Author.objects.raw(query=query, params=params))
+        self.assertProcessed(results, [author])
+        self.assertNoAnnotations(results)
+        self.assertEqual(len(results), 1)
+
+    def testManyToMany(self):
+        """
+        Test of a simple raw query against a model containing a m2m field
+        """
+        query = "SELECT * FROM raw_query_reviewer"
+        reviewers = Reviewer.objects.all()
+        self.assertSuccessfulRawQuery(Reviewer, query, reviewers)
+
+    def testExtraConversions(self):
+        """
+        Test to insure that extra translations are ignored.
+        """
+        query = "SELECT * FROM raw_query_author"
+        translations = {'something': 'else'}
+        authors = Author.objects.all()
+        self.assertSuccessfulRawQuery(Author, query, authors, translations=translations)
+
+    def testMissingFields(self):
+        query = "SELECT id, first_name, dob FROM raw_query_author"
+        for author in Author.objects.raw(query):
+            self.assertNotEqual(author.first_name, None)
+            # last_name isn't given, but it will be retrieved on demand
+            self.assertNotEqual(author.last_name, None)
+
+    def testMissingFieldsWithoutPK(self):
+        query = "SELECT first_name, dob FROM raw_query_author"
+        try:
+            list(Author.objects.raw(query))
+            self.fail('Query without primary key should fail')
+        except InvalidQuery:
+            pass
+
+    def testAnnotations(self):
+        query = "SELECT a.*, count(b.id) as book_count FROM raw_query_author a LEFT JOIN raw_query_book b ON a.id = b.author_id GROUP BY a.id, a.first_name, a.last_name, a.dob ORDER BY a.id"
+        expected_annotations = (
+            ('book_count', 3),
+            ('book_count', 0),
+            ('book_count', 1),
+            ('book_count', 0),
+        )
+        authors = Author.objects.all()
+        self.assertSuccessfulRawQuery(Author, query, authors, expected_annotations)
+
+    def testInvalidQuery(self):
+        query = "UPDATE raw_query_author SET first_name='thing' WHERE first_name='Joe'"
+        self.assertRaises(InvalidQuery, Author.objects.raw, query)
+
+    def testWhiteSpaceQuery(self):
+        query = "    SELECT * FROM raw_query_author"
+        authors = Author.objects.all()
+        self.assertSuccessfulRawQuery(Author, query, authors)
+
+    def testMultipleIterations(self):
+        query = "SELECT * FROM raw_query_author"
+        normal_authors = Author.objects.all()
+        raw_authors = Author.objects.raw(query)
+
+        # First Iteration
+        first_iterations = 0
+        for index, raw_author in enumerate(raw_authors):
+            self.assertEqual(normal_authors[index], raw_author)
+            first_iterations += 1
+
+        # Second Iteration
+        second_iterations = 0
+        for index, raw_author in enumerate(raw_authors):
+            self.assertEqual(normal_authors[index], raw_author)
+            second_iterations += 1
+
+        self.assertEqual(first_iterations, second_iterations)