From 3df72660560730393fc958700d2a3ab975c4b361 Mon Sep 17 00:00:00 2001
From: Jacob Kaplan-Moss <jacob@jacobian.org>
Date: Mon, 25 Aug 2008 12:56:06 +0000
Subject: [PATCH] Fixed #3575: use UPPER() instead ILIKE for postgres
 case-insensitive comparisons.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8536 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/db/backends/postgresql/base.py          |  8 ++++----
 django/db/backends/postgresql/operations.py    | 16 ++++++++++++----
 django/db/backends/postgresql_psycopg2/base.py |  8 ++++----
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 7bcda5b6f6..376d7ba2c8 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -70,9 +70,9 @@ class DatabaseFeatures(BaseDatabaseFeatures):
 class DatabaseWrapper(BaseDatabaseWrapper):
     operators = {
         'exact': '= %s',
-        'iexact': 'ILIKE %s',
+        'iexact': '= UPPER(%s)',
         'contains': 'LIKE %s',
-        'icontains': 'ILIKE %s',
+        'icontains': 'LIKE UPPER(%s)',
         'regex': '~ %s',
         'iregex': '~* %s',
         'gt': '> %s',
@@ -81,8 +81,8 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         'lte': '<= %s',
         'startswith': 'LIKE %s',
         'endswith': 'LIKE %s',
-        'istartswith': 'ILIKE %s',
-        'iendswith': 'ILIKE %s',
+        'istartswith': 'LIKE UPPER(%s)',
+        'iendswith': 'LIKE UPPER(%s)',
     }
 
     def __init__(self, *args, **kwargs):
diff --git a/django/db/backends/postgresql/operations.py b/django/db/backends/postgresql/operations.py
index 4eb5ead47c..01cc1fc8b7 100644
--- a/django/db/backends/postgresql/operations.py
+++ b/django/db/backends/postgresql/operations.py
@@ -36,10 +36,18 @@ class DatabaseOperations(BaseDatabaseOperations):
         return " DEFERRABLE INITIALLY DEFERRED"
 
     def lookup_cast(self, lookup_type):
-        if lookup_type in ('iexact', 'contains', 'icontains', 'startswith', 'istartswith',
-                             'endswith', 'iendswith'):
-            return "%s::text"
-        return "%s"
+        lookup = '%s'
+
+        # Cast text lookups to text to allow things like filter(x__contains=4)
+        if lookup_type in ('iexact', 'contains', 'icontains', 'startswith',
+                           'istartswith', 'endswith', 'iendswith'):
+            lookup = "%s::text"
+
+        # Use UPPER(x) for case-insensitive lookups; it's faster.
+        if lookup_type in ('iexact', 'icontains', 'istartswith', 'iendswith'):
+            lookup = 'UPPER(%s)' % lookup
+
+        return lookup
 
     def field_cast_sql(self, db_type):
         if db_type == 'inet':
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 61e440f577..6ecf86b705 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -40,9 +40,9 @@ class DatabaseOperations(PostgresqlDatabaseOperations):
 class DatabaseWrapper(BaseDatabaseWrapper):
     operators = {
         'exact': '= %s',
-        'iexact': 'ILIKE %s',
+        'iexact': '= UPPER(%s)',
         'contains': 'LIKE %s',
-        'icontains': 'ILIKE %s',
+        'icontains': 'LIKE UPPER(%s)',
         'regex': '~ %s',
         'iregex': '~* %s',
         'gt': '> %s',
@@ -51,8 +51,8 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         'lte': '<= %s',
         'startswith': 'LIKE %s',
         'endswith': 'LIKE %s',
-        'istartswith': 'ILIKE %s',
-        'iendswith': 'ILIKE %s',
+        'istartswith': 'LIKE UPPER(%s)',
+        'iendswith': 'LIKE UPPER(%s)',
     }
 
     def __init__(self, *args, **kwargs):