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Databases Mongo Basics Understanding MongoDB Store Your Blog In Mongo

Stamos Bolovinos
Stamos Bolovinos
4,320 Points

Problem accessing field

Consider this query:

var id = db.posts.find()[0].author;

db.users.find(id)                       //works
db.users.find(id).signupDate            //returns nothing
db.users.find()[0].signupDate           //works

What is the problem of the second query? Why can I not access the document objects property signupDate?

1 Answer

db.users.find(id) will return an Array. So you need to declare the location of the array which is 0. Try db.users.find(id)[0].signupDate.

Neil McPartlin
Neil McPartlin
14,662 Points

Kanishkah is right. What confused me was Stamos's 3rd suggestion appearing to work until I realised all 6 authors have exactly the same signup timestamp. So although the declared 'id' belongs to Roger Riola, if the 3rd entry is rewritten as db.users.find()[0].name, this reveals that the signupDate actually belongs to Sam Lund.

db.users.find(id)[0].signupDate is correct and db.users.find(id)[0].name confirms it belongs to Roger Riola.