Updated readme for #31

README.md

@@ -274,6 +274,13 @@ Or you can access the internal object directly:
 
 ### MongoDB specific operations
 
+**Upsert**
+
+Update or insert a document. Additional options for the update method are passed directly to the native update method.
+
+    DB::collection('users')->where('name', 'John')
+                           ->update($data, array('upsert' => true));
+
 **Push**
 
 Add an items to an array.