Fixed #10154: Allow combining F expressions with timedelta values.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15018 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 17 insertions, 0 deletions

diff --git a/django/db/backends/postgresql/operations.py b/django/db/backends/postgresql/operations.py
index e8ce3f242b..83fe7c21ec 100644
--- a/django/db/backends/postgresql/operations.py
+++ b/django/db/backends/postgresql/operations.py
@@ -27,6 +27,23 @@ class DatabaseOperations(BaseDatabaseOperations):
         else:
             return "EXTRACT('%s' FROM %s)" % (lookup_type, field_name)
 
+    def date_interval_sql(self, sql, connector, timedelta):
+        """
+        implements the interval functionality for expressions
+        format for Postgres:
+            (datefield + interval '3 days 200 seconds 5 microseconds')
+        """
+        modifiers = []
+        if timedelta.days:
+            modifiers.append(u'%s days' % timedelta.days)
+        if timedelta.seconds:
+            modifiers.append(u'%s seconds' % timedelta.seconds)
+        if timedelta.microseconds:
+            modifiers.append(u'%s microseconds' % timedelta.microseconds)
+        mods = u' '.join(modifiers)
+        conn = u' %s ' % connector
+        return u'(%s)' % conn.join([sql, u'interval \'%s\'' % mods])
+
     def date_trunc_sql(self, lookup_type, field_name):
         # http://www.postgresql.org/docs/8.0/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC
         return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name)