CODEWITHSUNDEEP
node.jsmongoose
ankitkhandelwal185
ankitkhandelwal185

Reputation: 1121

forEach in mongoose not working using nodejs

I am trying to get all consultation of a patient and if a patient has more than one consultation then i need to iterate through foreach/map, here is my implement of this but this is not working, please help

in below code when i am hitting the api then the response i am receiving is this: No default engine was specified and no extension was provided if i am running this code without foreach then it is working and i am getting doc length

router.post('/get/consultations', function(req, res){
        console.log("consultation"+req.body.patient_id);
        var dc = {};
        consultation.find({"patient":req.body.patient_id}).forEach(function(doc){
                console.log(doc.length);
                //dc.push(doc);
        });
        res.json(dc);

    });

Upvotes: 0

Views: 393

Answers (1)

kicito
kicito

Reputation: 99

According to Mongoose Doc http://mongoosejs.com/docs/queries.html

When a callback function:

  • is passed, the operation will be executed immediately with the results passed to the callback.
  • is not passed, an instance of Query is returned, which provides a special query builder interface.

since your statement 

consultation.find({"patient":req.body.patient_id})

didn't pass callback function as an argument. This statement returns a Query object which you can execute by using .exec eg.

// .find returns a Query object
var query = Person.find({ 'name.last': 'Ghost' });

// execute the query at a later time
query.exec(function (err, person) {
  if (err) return handleError(err);
  console.log('%s %s is a %s.', person.name.first, person.name.last, person.occupation) // Space Ghost is a talk show host.
})

so your code should be either one of these way

// using exec     
consultation.find({"patient":req.body.patient_id}).exec(function(docs){
docs.forEach(function(doc){
    console.log(doc.length);
});

// using callback     
consultation.find({"patient":req.body.patient_id}, function(err,docs){
    docs.forEach(function(doc){
         console.log(doc.length);
    });
});

// using promise (mongoose 4+)
consultation.find({"patient":req.body.patient_id}).then( function(docs){
    docs.forEach(function(doc){
         console.log(doc.length);
    });
});

Upvotes: 3

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