change varibable value using mongoose query result

Question

i have code blow and need to replace the "doc" (query result) with projectsDocument, but projectsDocument not defined in the function,please help me!!!!

var projectsDocument, categoryDocument; //empty
    projectsModel.find({}, {}, (err, doc) => {
        if (err) return next(err);
        if (doc) {
            projectsDocument = doc; 

        }
    });
    console.log(projectsDocument); //want to projectsDocument be equals to doc

[SOLVED]

i change my code to this and it works

    router.get('/', async(req, res, next) => {

    await projectsModel.find().then(function(doc) {
        projectsDocument = doc;
    }).catch(function(error) {
        console.log(error);
    });

});

This question is not clear on what you're trying to do, try this first :: `projectsModel.find({}).toArray((err, doc) => { if (err) return next(err); if (doc) { projectsDocument = doc; } });` — whoami - fakeFaceTrueSoul, Apr 29 '20 at 14:26
its a async call back so `console.log(projectsDocument);` execute before callback finished .That's why its undefined . you could console.log inside the exec callback i will work — prasanth, Apr 29 '20 at 14:32

Zain Ul Abideen · Accepted Answer · 2020-04-29T15:02:39.753

0

Because Javascript is async in nature means it does not execute instructions such as API calls synchronously (does not wait for the response).

Mongoose version > 4.0

projectsModel.find()
.then(function(doc){
   if (doc) {
        projectsDocument = doc; 
    }
})
.catch(function(err) {})

Mongoose version < 4.0

var projects = projectsModel.find().exec() //returns promise

projects.then(function(project){
    if (project) {
       projectsDocument = project;
    }
})

edited Apr 29 '20 at 15:02

answered Apr 29 '20 at 14:33

Zain Ul Abideen

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i have tried this but nothing happend! – Amir Mohammad Rivand Apr 29 '20 at 14:45
@AmirMohammadRivand What you are getting in the `doc`? – Zain Ul Abideen Apr 29 '20 at 14:47
clearly query result as Object – Amir Mohammad Rivand Apr 29 '20 at 14:51
which version of mongoose you are using? – Zain Ul Abideen Apr 29 '20 at 14:52
i use mongoose ver 5.* – Amir Mohammad Rivand Apr 29 '20 at 15:45
@AmirMohammadRivand That's strange, even with first approach you are getting same problem? Did you try `console.log(doc)` to check if `doc` has a an object? – Zain Ul Abideen Apr 29 '20 at 15:58
thank you! it is working – Amir Mohammad Rivand Apr 29 '20 at 16:00
What was the issue? You can thank me by accepting the answer if it helped you ;) – Zain Ul Abideen Apr 29 '20 at 16:00
you can see my new code at the top – Amir Mohammad Rivand Apr 29 '20 at 16:05
cool, Happy it helped :) – Zain Ul Abideen Apr 29 '20 at 16:20

change varibable value using mongoose query result

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