返回Model.create(arr).exec()在猫鼬中不起作用 [英] return Model.create(arr).exec() is not working in mongoose

问题描述

我听说exec兑现了承诺"，所以我正在使用exec进行异步调用.这个问题是我其他问题的启发.解说员说我的代码不起作用，因为:

I heard that exec "returns a promise" so I'm using exec it do asynchronous calls. This question is inspired my other question. The commentator said my code is not working because :

您正在同步使用异步代码

You are using asynchronous code synchronously

我正在尝试通过使用以下代码来修复该问题.不知道这段代码是否会使它不同步，但我听说这会有所帮助.

I was trying to fix that by using the below code. Don't know if this code will make it not sync but I heard that promises help with that.

所以我有这个，我不能创建(保存)数据，但是可以删除它.为什么不能为create使用与remove相同的模式?

so I have this and I cannot create(save) the data but I can delete it. why cant I use the same pattern for create as i did for remove?

var Comp = require("./models/company.js");
  var arr = [
    {name : "comp1",industry : "industry1", ranking: 20},
    {name : "comp2",industry : "industry2", ranking: 5},
    {name : "comp3",industry : "industry3", ranking: 10}
  ]


Comp.find({}).exec()
    .then(function(docs){
        return Comp.remove({}).exec()
        .then(function(){
            console.log("deleted")
        })
    })
    .then(function(){
        return Comp.create(arr).exec()
        .then(function(data){
            console.log(data)
        })
    })

您能帮我实现我最初的目标吗?

and can you help get to my original goal which was in my other question.

推荐答案

then函数不返回承诺， exec可以返回！

所以您需要做return Comp.remove({}).exec()

Comp.find({}).exec()
.then(function(docs){
    return Comp.remove({}).exec();
})
.then(function(result_of_remove){
    return Comp.create(arr).exec();
})
.then(function(result_of_create){
    ....
})

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