具体错误是：

{ [ConnectionError: Failed to connect to localhost:1433 - connect ECONNREFUSED] name: 'ConnectionError', message: 'Failed to connect to localhost:1433 - connect ECONNREFUSED', code: 'ESOCKET' }

我的代码，主要是按官网上的：

var sql = require('mssql');
    var config = {
        user: 'sa',
        password: '123456',
        server: 'localhost', // You can use 'localhost\\instance' to connect to named instance
        database: 'expressdb'
    };
    var connection = new sql.Connection(config);
    connection.connect(function(err) {
        if(err){
            var util = require('util');
            var tmp = util.inspect(err);
            res.send(tmp);
        }else{
            res.send("ok");
        }
    });

大家是否遇到过同样问题，在网上一直接不到答案？