我正在使用异步瀑布并遇到一些问题

Question

I simply want to fetch the details from a document called 'slt_timesheet'. And I'm using async-waterfall to run 2-3 function in a sequence.

If I use the 'get' method to get the details of slt_timesheet then I got all the details regarding my slt-timesheet but if I use async-waterfall I am unable to get the details from document.

    const express = require('express');
    const app=express();

    const async=require("async");
    const waterfall=require('async-waterfall');

    const TIMESHEET_DETAILS = require('../Models/slt_timesheet');

    //For filing the timesheet
          router.post('/postTimesheet',(req,res)=>{
            let monthFromClient=req.body.month;
            let projectArrayFromClient=req.body.projectArray;
            let activityArray=req.body.activityArray;
            let hoursArrayForAMonth=req.body.hoursArray;

            let currentDateObject = new Date();
            let lastMonthDateObject= new Date(currentDateObject.getFullYear(),currentDateObject.getMonth()+1,0);
            let nowMonth = monthList[lastMonthDateObject.getMonth()];
            let thisYear = lastMonthDateObject.getFullYear();
            let response;
            let onlyTimeSheetData=[];
            let timesheetRecord;

            try {
               //First check here request month is same as the current method
              if(monthFromClient===nowMonth && req.session.email!=null){
           //async waterfall starts here 
                waterfall([
                    function getTimesheet(callback){
                      console.log('waterfall execution starts here');

                      try {
                        timesheetRecord = TIMESHEET_DETAILS.findOne({email:req.session.email});
                        console.log(timesheetRecord.email);
                        // onlyTimeSheetData=timesheetRecord.timesheetData[0];
                      } catch (e) {
                        console.log(e);
                        callback(e,null);
                        return;
                      }

                      console.log(onlyTimeSheetData);
                      callback(null,onlyTimeSheetData);
                    },

                    function insertNewDataInFormat(err,onlyTimeSheetData) {
                      if(err){
                        console.error(err);
                      }else {
                        console.log(onlyTimeSheetData);
                      }

                    }
                ]);
                response='successful';
              }else {
                response='not successful';
              }
            } catch (e) {
              console.error('error find in main catch'+e);
            } finally {
              res.send(response);
            }

Answer 1

findOne method is an asynchronous call and you are calling it without callback. Try calling findOne with either callback or promises.