Query sub documents in array of parent document

Question

db.animals

{\'animal\':\'monkey\',
 \'quantity:3
 \'id\' : 001}
{\'animal\':\'pig\',
 \'quantity:5
 \'id\' : 002}
{\'animal\':\'cow\',
 \'quantity:3
 \'id\' : 00         


        

Answer 1

There are no joins in MongoDB so you have to do it in two steps.

In the shell:

var john = db.people.findOne({person: 'john'})
db.animals.find({id: {$in: john.have}})