我已经研究了 mongoose 三天了,我对这两种方法的使用有点困惑(我知道“mongoose.connection()”将来会被弃用......)
问题是:当我试图转换(从“mongoose.connection()”到“mongoose.createConnection()”)这个例子的action.js文件https://gist.github.com/2785463不为我工作...
有我的代码...
var mongoose = require('mongoose'),
db = mongoose.createConnection('localhost', 'test');
db.on('error', function () {
console.log('Error! Database connection failed.');
});
db.once('open', function (argument) {
console.log('Database connection established!');
mongoose.connection.db.collectionNames(function (error, names) {
if (error) {
console.log('Error: '+ error);
} else {
console.log(names);
};
});
});
还有我的终端输出(在我的 ubuntu 终端上输入“node test.js”..)
Database connection established!
/home/_user_/Scrivania/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:437
throw err;
^
TypeError: Cannot call method 'collectionNames' of undefined
at NativeConnection.<anonymous> (/home/_user_/Scrivania/test2.js:11:25)
at NativeConnection.g (events.js:192:14)
at NativeConnection.EventEmitter.emit (events.js:93:17)
at open (/home/_user_/Scrivania/node_modules/mongoose/lib/connection.js:408:10)
at NativeConnection.Connection.onOpen (/home/_user_/Scrivania/node_modules/mongoose/lib/connection.js:415:5)
at Connection._open (/home/_user_/Scrivania/node_modules/mongoose/lib/connection.js:386:10)
at NativeConnection.doOpen (/home/_user_/Scrivania/node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js:47:5)
at Db.open (/home/_user_/Scrivania/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:287:14)
at Server.connect.connectCallback (/home/_user_/Scrivania/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:235:7)
at g (events.js:192:14)