你好，我如何计算一个公共函数来路由并在 Postman 上检查它？这是我的密码

router.post('/post_regular_hours/:employee_id/',function(request,response,next){
    var id = request.params.employee_id;
    var time_in = request.params.time_in;
    var time_out = request.params.time_out;
    // const timein = request.params.time_in;
    // const timeout = request.params.time_out;
    knexDb.select('*')
            .from('employee_attendance')
            .where('employee_id',id)
            .then(function(result){

                res.send(compute_normal_hours(response,result,diff))

            })
});

function compute_normal_hours(res,result,diff){

    let time_in = moment(time_in);
    let time_out = moment(time_out);

    let diff = time_out.diff(time_in, 'hours');

    return diff;

}

我希望差异得到 Postman 作为结果张贴在这里是我的代码app.js。如何将mysql查询中的数据调用到函数中，并在router post上返回计算出的数据，或者你们能给出正确的术语吗。

var express = require('express');
var mysql= require('mysql');
var employee = require('./routes/employee');
var time_record = require('./routes/time_record');
var admin_employee = require('./routes/admin_employee');
var tar = require('./routes/tar');
var Joi = require('joi');

var app = express();

app.get('/hello',function(req,res){
  var name = "World";
  var schema = {
      name: Joi.string().alphanum().min(3).max(30).required()
  };
  var result = Joi.validate({ name : req.query.name }, schema);
  if(result.error === null)
  {
     if(req.query.name && req.query.name != '')
    {
      name = req.query.name;
    }
    res.json({
      "message" : "Hello "+name + "!"
    });
  }
  else
  {
    res.json({
      "message" : "Error"
    });
  }

}); 

//Database connection
app.use(function(req, res, next){
    global.connection = mysql.createConnection({
        host     : 'locahost',
        user     : 'dbm_project',
      password : 'dbm1234',
        database : 'dbm_db'
    });
    connection.connect();
    next();
});

app.use('/', employee);
app.use('/employee', time_record);
app.use('/admin', admin_employee);
app.use('/tar', tar);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

app.listen(8000,function(){
  console.log("App started on port 8000!");
});

module.exports = app;

这是我代码的app.js。如何将mysql查询中的数据调用到函数中，并将计算出的数据返回到路由器po