Factored out database-specific date_extract behavior into dbmod.get_date_extract_sql(). Refs #46

git-svn-id: http://code.djangoproject.com/svn/django/trunk@159 bcc190cf-cafb-0310-a4f2-bffc1f526a37

4 files changed, 10 insertions, 1 deletions

diff --git a/django/core/db/__init__.py b/django/core/db/__init__.py
index deede3d7ca..8c20ef4068 100644
--- a/django/core/db/__init__.py
+++ b/django/core/db/__init__.py
@@ -24,5 +24,6 @@ dictfetchmany = dbmod.dictfetchmany
 dictfetchall = dbmod.dictfetchall
 dictfetchall = dbmod.dictfetchall
 get_last_insert_id = dbmod.get_last_insert_id
+get_date_extract_sql = dbmod.get_date_extract_sql
 OPERATOR_MAPPING = dbmod.OPERATOR_MAPPING
 DATA_TYPES = dbmod.DATA_TYPES
diff --git a/django/core/db/backends/mysql.py b/django/core/db/backends/mysql.py
index 3c0924e53f..001a32c191 100644
--- a/django/core/db/backends/mysql.py
+++ b/django/core/db/backends/mysql.py
@@ -62,6 +62,10 @@ def get_last_insert_id(cursor, table_name, pk_name):
     cursor.execute("SELECT LAST_INSERT_ID()")
     return cursor.fetchone()[0]
 
+def get_date_extract_sql(lookup_type, table_name):
+    # lookup_type is 'year', 'month', 'day'
+    return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), table_name)
+
 OPERATOR_MAPPING = {
     'exact': '=',
     'iexact': 'LIKE',
diff --git a/django/core/db/backends/postgresql.py b/django/core/db/backends/postgresql.py
index ded611376d..df7829f683 100644
--- a/django/core/db/backends/postgresql.py
+++ b/django/core/db/backends/postgresql.py
@@ -61,6 +61,10 @@ def get_last_insert_id(cursor, table_name, pk_name):
     cursor.execute("SELECT CURRVAL('%s_%s_seq')" % (table_name, pk_name))
     return cursor.fetchone()[0]
 
+def get_date_extract_sql(lookup_type, table_name):
+    # lookup_type is 'year', 'month', 'day'
+    return "EXTRACT('%s' FROM %s)" % (lookup_type, table_name)
+
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg
 # use mx.DateTime by default.
diff --git a/django/core/meta.py b/django/core/meta.py
index 68ee1f2b22..8e7c22596e 100644
--- a/django/core/meta.py
+++ b/django/core/meta.py
@@ -1006,7 +1006,7 @@ def _get_where_clause(lookup_type, table_prefix, field_name, value):
     if lookup_type in ('range', 'year'):
         return '%s%s BETWEEN %%s AND %%s' % (table_prefix, field_name)
     elif lookup_type in ('month', 'day'):
-        return "EXTRACT('%s' FROM %s%s) = %%s" % (lookup_type, table_prefix, field_name)
+        return "%s = %%s" % db.get_date_extract_sql(lookup_type, table_prefix + field_name)
     elif lookup_type == 'isnull':
         return "%s%s IS %sNULL" % (table_prefix, field_name, (not value and 'NOT ' or ''))
     raise TypeError, "Got invalid lookup_type: %s" % repr(lookup_type)