Question

我尝试聚合我的两个MongoDB数据库，但是现在我从收集信息中遇到了问题。

所以，我尝试做的是从两个数据库中创建一个object。我的问题是函数User.find()和EmployersSchemaDB.find()在聚合后不会将变量/ obj推到外面。你可以在下面的代码中看到它......

我做错了什么？

UPD根据评论中的回答：

router.route('/employers')
.get((req, res) => {
    function getDate() {
        console.log('Hi');
        let obj = {
            userCookies: '',
            EmployersObj: {}
        } 
        const userFind = User.find((err, users) => {
            if (err) { res.send(err) }
            if (req.session.userId !== undefined) {
                obj.userCookies = req.session.userId;
                return obj.userCookies;
            } else {
                obj.userCookies = '';
                return obj.userCookies;
            }
        });

        const employerFind = EmployersSchemaDB.find((err, employers) => {
            if (err) { res.send(err) }
                obj.EmployersObj = employers;
                return obj.EmployersObj;
        });

        Promise.all(userFind, employerFind).then(responseArr => { 
            return res.json(responseArr);
        }).catch(err => console.log(err));
    }
    getDate();
})

错误日志：

Server running on port 3016
19:23:24 Server.1   |  Hi
19:23:24 Server.1   |  TypeError: undefined is not a function
19:23:24 Server.1   |      at Function.all (<anonymous>)
19:23:24 Server.1   |      at getDate (C:\Users\\Desktop\react\mern\Server\server.js:194:21)
19:23:24 Server.1   |      at router.route.get (C:\Users\\Desktop\react\mern\Server\server.js:198:9)
19:23:24 Server.1   |      at Layer.handle [as handle_request] (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\layer.js:95:5)
19:23:24 Server.1   |      at next (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\route.js:137:13)
19:23:24 Server.1   |      at Route.dispatch (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\route.js:112:3)
19:23:24 Server.1   |      at Layer.handle [as handle_request] (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\layer.js:95:5)
19:23:24 Server.1   |      at C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:281:22
19:23:24 Server.1   |      at Function.process_params (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:335:12)
19:23:24 Server.1   |      at next (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:275:10)
19:23:24 Server.1   |      at Function.handle (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:174:3)
19:23:24 Server.1   |      at router (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:47:12)
19:23:24 Server.1   |      at Layer.handle [as handle_request] (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\layer.js:95:5)
19:23:24 Server.1   |      at trim_prefix (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:317:13)
19:23:24 Server.1   |      at C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:284:7
19:23:24 Server.1   |      at Function.process_params (C:\Users\\Desktop\react\mern\node_modules\express\lib\router\index.js:335:12)
ayer.js:95:5)

Answer 1

可能因为您的EmployersSchemaDB.find()方法返回了一个承诺。您可以使用Promise.all执行两个查询，然后在完成后处理响应：

router
  .route('/employers')
  .get((req, res) => {
    const userFind = User.find();
    const employerFind = EmployersSchemaDB.find();

    Promise.all([userFind, employerFind])
      .then(responseArr => {
        return res.json(formatResponse(responseArr, '' || req.session.userId));
      })
      .catch(err => console.log(err));
  })

function formatResponse(arr, cookies) {
  console.log('formatRes hi', arr);
  const obj = {
    userCookies: cookies,
    usersRes = arr[0],
    employersRes: arr[1]
  }
}

如何汇总来自两个函数的数据？

1 个答案: