Passing variable in db.collection.findOne( { parm : value }

Question

I am trying to create a method that will fetch a record from a collection based on a parameter and a value something like.

where parm is for instance the _id field in this schema.

getRecord('_id', '1234567876543')

getRecord(parm, value){
    db.collection.findOne( { parm : value } , function(err, item) {
        if (err) {
            console.error(err);
        }else if (item === null ) {
            console.error('record does not exist');
        }else {
            Record = JSON.stringify(item); 
        }
    });
}

What is happening is that this code is trying to fetch the colum parm from the table which does not exist, returning record does not exist every time.

How can I pass the value of the param in the findOne Query?

score 5 · Accepted Answer · answered Oct 28 '17 at 19:30

5

If you wish to pass a variable in the key part of an object, you can pass it by using square brackets. In your case, do it like:

db.collection.findOne( { [parm] : value } , function(err, item) {

Or maybe, you could just assign it to an object like:

var query = {};
query[parm] = value;
db.collection.findOne( query , function(err, item) {...})

answered Oct 28 '17 at 19:30

Parijat Purohit

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1

@JoaoFilipeClementeMartins haha.. glad I could help :) – Parijat Purohit Oct 28 '17 at 19:34
3

@JoaoFilipeClementeMartins please approve this answer as correct. – semanser Oct 28 '17 at 19:34
I will but need to wit 9 minutes. – JoaoFilipeClementeMartins Oct 28 '17 at 19:34
1

@semanser That blissful comment of yours ;) – Parijat Purohit Oct 28 '17 at 19:44

Passing variable in db.collection.findOne( { parm : value }

1 Answers1