搭建时出现错误了：express是4.12.1,node是0.12.0 依赖的包是： “mongodb”: “1.4.15”,“express-session”: “1.9.1”,“connect-mongo”: “0.8.0”,“bson”: “0.2.0”,“connect-flash”: "0.1.1" D:\node\microblog\node_modules\mongodb\lib\mongodb\connection\base.js:246 throw message; ^ TypeError: Cannot read property ‘length’ of undefined at processResults (D:\node\microblog\node_modules\mongodb\lib\mongodb\db.js: 1603:31) at D:\node\microblog\node_modules\mongodb\lib\mongodb\db.js:1641:20 at D:\node\microblog\node_modules\mongodb\lib\mongodb\db.js:1179:7 at D:\node\microblog\node_modules\mongodb\lib\mongodb\db.js:1912:9 at Server.Base._callHandler (D:\node\microblog\node_modules\mongodb\lib\mong odb\connection\base.js:448:41) at D:\node\microblog\node_modules\mongodb\lib\mongodb\connection\server.js:4 81:18 at MongoReply.parseBody (D:\node\microblog\node_modules\mongodb\lib\mongodb
responses\mongo_reply.js:68:5) at null.<anonymous> (D:\node\microblog\node_modules\mongodb\lib\mongodb\conn ection\server.js:439:20) at emit (events.js:107:17) at null.<anonymous> (D:\node\microblog\node_modules\mongodb\lib\mongodb\conn ection\connection_pool.js:201:13)