分离出insert，写操作采用w:1

core/model/Model.coffee

@@ -23,8 +23,8 @@ module.exports = class Model
   get : (attr) ->
     @data[attr]
 
-  save : (data, callback) ->
-    @collection().insert data, {}, (err, docs) =>
+  insert : (data, callback) ->
+    @collection().insert data, {w:1}, (err, docs) =>
       throw err if err
       if callback
         results = []
@@ -35,6 +35,8 @@ module.exports = class Model
           results = @create docs[0]
         callback err, results
 
+  update : (newObj , opts = {},callback) ->
+
   @find : (data, opts = {}, callback = null) ->
     if _.isFunction data
       callback = data

core/model/User.coffee

@@ -20,4 +20,4 @@ module.exports = class User extends Model
       setting: {}
       attribure: {}
       tokens: []
-    @save data, callback
+    @insert data, callback