NodeJS和MsSQL：request.query不返回calblack

我试图做我的SQL Server上的查询，连接工作正常，并在我更改密码时出现错误。 “错误”是在request.query（sql，callback）上，这个函数没有返回一个callback

连接码：

var sql = require('mssql'); var config = { user: 'user', password: 'password', server: 'ip', database: 'database', connectionTimeout: '5000', requestTimeout: '5000', options: {encrypt: true} }; var pool = function(){ var conn = new sql.Connection(config, function(err){ var request = new sql.Request(conn); //console.dir(request); return request; }); return conn; } module.exports = function(){ return pool; } 

DAO：

 function CampanhaDAO(connection){ this._connection = connection; //console.log(this._connection) } CampanhaDAO.prototype.getCampanhas = function(){ var sql = "SELECT * FROM notificacao_campanha"; this._connection.query(sql, function(err, recordset){ console.log(recordset); }); }; module.exports = function(){ return CampanhaDAO; }; 

控制器：

 module.exports.campanhas = function(app, req, res){ var connection = app.config.dbConnection(); var campanhaDAO = new app.dao.CampanhaDAO(connection); campanhaDAO.getCampanhas(function(error, result){ console.log("gerou"); res.send(result); }); } 

谁能帮我？