node.js - 使用 async wait 执行多个数据库查询

Question

我试图从一些 mongodb 集合中获取一些记录的计数，作为 http 请求的一部分。我有以下代码来处理 http 请求，但在获取其他信息时遇到一些困惑。

app.get('/shopdetails/:id', function(req, res) {
  Shop.findOne({_id: req.params.id})
    .exec(function(err, data) {
     if (err) { return res.status(500).send() };

     const id = data._id;
     //1. Get number of employees count from Employee collection
     //2. Get number of product count from Product collection
     // Each collection has a field _shop as a ref field so I can
     // do 
     // Employee.countDocuments({_shop: id}) or
     // Product.countDocuments({_shop: id})
  });
});

如何在返回响应之前使用 async/await 获取每个计数？

Answer 1

试试这个

app.get('/shopdetails/:id', async function(req, res) {
  try{
   const getData = await Shop.findOne({_id: req.params.id});
   const getDataEmploye = await Employee.countDocuments({_shop: id});
   const getDataProduct = await Product.countDocuments({_shop: id});
   // after that, you will get respons from Shop and Employe collection. Check console.log(getData), console.log(getDataEmploye), console.log(getDataProduct)
   //you can doing anything after get that collection data
   } catch(err){
    console.log(err)
   }

  });
});

希望这条线索能帮到你。谢谢