How to query and get value from list in single document

Question

I am trying to query a mongodb list in a single document. As shown below, I would like to match the code and get wheels value. if code = car then query should return wheels and allowed value for that list element. Below is a list from single document.

"vehicles" : [ 
        {
            "code" : "car",
        "wheels":4,
            "allowed": True
        }, 
        {
            "code" : "Tuk Tuk",
        "wheels":4
            "allowed":True
        }, 
        {
            "code" : "Bike",
        "wheels":4
            "allowed":False
        }]

score 0 · Accepted Answer · answered Oct 14 '19 at 11:44

0

you can try like this

db.collectionName.find({"vehicles.code" : "car" }, {"vehicles.wheels" : 1 , "vehicles.allowed" : 1}).pretty() here "vehicles.code" : "car" is the filter and "vehicles.wheels" : 1 will display the only wheels value and won't display any other fields

answered Oct 14 '19 at 11:44

Ranga Reddy

54
1
7

this will return list of wheels and allowed value for the document including Tuk Tuk and Bike – user123987 Oct 14 '19 at 11:47
It means it didn't apply the filter "vehicles.code" : "car" , Please check once with your query or else post the query – Ranga Reddy Oct 14 '19 at 11:53
given code is list from single document. You are filtering documents in collection. But I want filter the list. – user123987 Oct 14 '19 at 12:08
you may try like this ` db.Vehiclestest.find({vehicles : {$elemMatch : {"code" :"car"}}} , {'vehicles.$':1}).pretty() ` – Ranga Reddy Oct 14 '19 at 12:32
update the answer with your code from last comment. – user123987 Oct 15 '19 at 05:17

How to query and get value from list in single document

1 Answers1