Changeset 6515

Timestamp:

10/14/07 20:20:10 (11 months ago)

Author:

mtredinnick

Message:

queryset-refactor: Made sure the ordering columns in a distinct() query only
include the columns we are selecting on. This avoids some PostgreSQL problems
and leads to more efficient queries to boot. Refs #5321.

Files:

• django/branches/queryset-refactor/django/db/models/sql/query.py (modified) (5 diffs)
• django/branches/queryset-refactor/tests/regressiontests/queries/models.py (modified) (3 diffs)

django/branches/queryset-refactor/django/db/models/sql/query.py

@@ -343 +343 @@
-        qn = self.quote_name_unless_alias
-        result = []
+        aliases = []
-        if self.select:
-            for col in self.select:
-                if isinstance(col, (list, tuple)):
-
+
+
+
-                else:
-                    result.append(col.as_sql(quote_func=qn))
+                    if hasattr(col, 'alias'):
+                        aliases.append(col.alias)
-        else:
-            table_alias = self.tables[0]
-            result = ['%s.%s' % (qn(table_alias), qn(f.column))
-                    for f in self.model._meta.fields]
+            aliases = result[:]
-
-        # We sort extra_select so that the result columns are in a well-defined
@@ -360 +366 @@
-        result.extend(['(%s) AS %s' % (col, alias)
-                for alias, col in extra_select])
+        aliases.extend(self.extra_select.keys())
+
+        self._select_aliases = dict.fromkeys(aliases)
-        return result
-
@@ -436 +445 @@
-            ordering = self.order_by or self.model._meta.ordering
-        qn = self.quote_name_unless_alias
+        distinct = self.distinct
+        select_aliases = self._select_aliases
-        result = []
-        for field in ordering:
@@ -455 +466 @@
-                col, order = get_order_dir(field)
-                table, col = col.split('.', 1)
-
-
+
+
+
-            elif get_order_dir(field)[0] not in self.extra_select:
-                # 'col' is of the form 'field' or 'field1__field2' or
@@ -462 +474 @@
-                for table, col, order in self.find_ordering_name(field,
-                        self.model._meta):
-
+
+
+
-            else:
-                col, order = get_order_dir(field)
-
+
+
+
-        return result
-

django/branches/queryset-refactor/tests/regressiontests/queries/models.py

@@ -15 +15 @@
-class Note(models.Model):
-    note = models.CharField(maxlength=100)
+    misc = models.CharField(maxlength=10)
-
-    class Meta:
@@ -92 +93 @@
->>> t5.save()
-
-
+, misc='foo'
->>> n1.save()
-
+, misc='bar'
->>> n2.save()
-
+, misc='foo'
->>> n3.save()
-
@@ -330 +331 @@
->>> Item.objects.filter(Q(creator__name='a3', name='two')|Q(creator__name='a4', name='four'))
-[<Item: four>]
+
+Bug #5321
+>>> Note.objects.values('misc').distinct().order_by('note', '-misc')
+[{'misc': u'foo'}, {'misc': u'bar'}]
-"""}
-