Mongoose:将承诺作为其他函数的参数

I am trying to get a good understanding of how to work with promises, mostly because I want to query data and then use that data to query other data

我试图更好地理解如何使用承诺，主要是因为我想查询数据，然后使用这些数据查询其他数据

I have this Schema :

我有这个模式:

var serviceSchema = new Schema({
name: String,
});

And this method on it :

这个方法是

serviceSchema.statics.getIdByName = function getIdByName (serviceName) {

this.findOne({name :serviceName }).exec(function(err, service){
    if(err) console.log(err)

    return service._id

})
}

In my code I would like to do something like :

在我的代码中，我想做如下的事情:

var service_id = Service.getIdByName("facebook")
otherSchema.findOne({service : service_id}).exec(...)

but service_id is a promise so the query isn't right, I don't want to be in callback hell and calling models inside of callbacks etc I have tried async with something like

但是service_id是一个承诺，所以查询是不对的，我不想在回调中调用回调模型等等，我尝试过异步

async.series([getVariables], function(err, results){
otherSchema.findOne({service : service_id}).exec(...)})

Where getVariables is :

getVariables在哪里:

function getVariables(callback1) {
if(service_id!=undefined) {
    callback1(serviceID)
}}

Any help on how to achieve this is more than welcome! thanks a lot

任何关于如何实现这一点的帮助都是非常受欢迎的!非常感谢

2 个解决方案

#1

try this exec() returns promise.

试试这个exec()返回承诺。

serviceSchema.statics.getIdByName = function getIdByName(serviceName) {
    return this.findOne({
        name: serviceName
    }).exec();
}

Call getIdByName function

调用getIdByName函数

Service.getIdByName("facebook").then((data) => {
    console.log(data)
})

#2

The answer to this is actually using async/await and and do var x = await Model.findOne().exec()

答案实际上是使用async/ wait和do var x = wait Model.findOne().exec()

or any function that returns a promise, then you can use x anywhere in the code

或者任何返回承诺的函数，然后你可以在代码的任何地方使用x

#1