nodejs 异步编程async/await

参考：https://www.jianshu.com/p/2132904b9768

在路由js中

router.get('/', function(req, res, next) {
    res.render('index', { title: 'Express' });
});
router.post('/',async function (request,response) {
    var userName=request.body.userName;
    var password=request.body.password;
    var result=await login.panUser(userName,password);
    console.log("/routes/login / result");
    console.log(result);
    response.send(result);
})
module.exports = router;

在路由调用的js文件login.js中

const global=require('./global');
var Promise=require('Promise');
const login={
    panUser:async function (userName,password) {
            var sql = "select * from account where userName =" + userName;
            console.log("sql" + sql);
            var result=await global.db.checkPlayer(userName);
            console.log("/game/login panUser() result" + result);
            if(result==null||result=='')
            {
                console.log("/game/login panUser() if");
                result="no";
            }
            else
            {
                console.log("/game/login panUser() else");
                var dbPassword = result[0]['password'];
                console.log("/game/login panUser() Password)");
                console.log("/game/login panUser() Password)"+password+"dbPassword="+dbPassword);
                if (password == dbPassword) {
                    result = true;
                }
                else {
                    result = false;
                }
            }
            console.log("/game/login panUser() resolve(result)");
            console.log(result);
        return result;
    }
}

在login.js调用的db文件

 //查询玩家
    that.checkPlayer =async function (userName) {
        return new Promise(function(resolve, reject) {
            //查找玩家数据
            let sql = "select * from account where  userName = " + userName + ";";
            try{
                query(sql, function (err, data) {
                    if (err) {
                        data=null;
                        console.log('err = ' + err);
                    }
                    console.log('check player = ' + JSON.stringify(data));
                    //cb(err, data);
                    resolve(data);
                });
            }
            catch (event)
            {
                resolve(null);
            }

        });
    };

使用全局变量文件global

const db=require('./../utility/http/db');
const global={};
global.db=db();
module.exports= global;

踩坑：

在login.js中 需要用 await 来调用db中的函数，不能使用

return new Promise(function(resolve, reject)