Errors doing mongodb nested query - mongodb-query

Question

I am having a little trouble with nested queries in mongodb.
I have a collection with the following structure --
{
"_id" : Objectid(..),
"result" : {
"name" : nameValue,
"reference" : base64Value,
"city" : cityValue
}
}
Now I am to do two queries in the mongo shell -
search for a specific reference value (so query for equality)
I am using the following query -
db.TestCollection.find("result.reference" : a3d245e343 }
but I get nothing when I know the record is there in the collection
search and print for all city values.
I am looking to print something like this--
{ "city": "new york city" }
{ "city" : "brooklyn" }
... etc
For this I use this query --
db.TestCollection.find( {}, {"results.city", 1} )
For this I do not get the output I was hoping for but only get a list of all "_id" values like this --
{ "_id" : ObjectId("52e466bd562bdb7b1b320d1d") }
{ "_id" : ObjectId("52e466be562bdb7b1b320d1e") }
{ "_id" : ObjectId("52e466be562bdb7b1b320d1f") }
{ "_id" : ObjectId("52e466bf562bdb7b1b320d20") }
{ "_id" : ObjectId("52e466bf562bdb7b1b320d21") }
{ "_id" : ObjectId("52e466bf562bdb7b1b320d22") }
{ "_id" : ObjectId("52e466c0562bdb7b1b320d23") }
{ "_id" : ObjectId("52e466c0562bdb7b1b320d24") }
{ "_id" : ObjectId("52e466c1562bdb7b1b320d25") }
{ "_id" : ObjectId("52e466c1562bdb7b1b320d26") }
{ "_id" : ObjectId("52e466c2562bdb7b1b320d27") }
{ "_id" : ObjectId("52e466c2562bdb7b1b320d28") }
{ "_id" : ObjectId("52e466c2562bdb7b1b320d29") }
{ "_id" : ObjectId("52e466c3562bdb7b1b320d2a") }
{ "_id" : ObjectId("52e466c3562bdb7b1b320d2b") }
{ "_id" : ObjectId("52e466c4562bdb7b1b320d2c") }
{ "_id" : ObjectId("52e466c4562bdb7b1b320d2d") }
{ "_id" : ObjectId("52e466c4562bdb7b1b320d2e") }
{ "_id" : ObjectId("52e466c5562bdb7b1b320d2f") }
{ "_id" : ObjectId("52e466c5562bdb7b1b320d30") }
has more
What am I doing wrong?
I know there are lot of questions regarding queries but I am still wrapping my head around the whole idea. Thanks for helping a newbie out.

Answer 1

I found the issue with both the commands -
For some reason the condition should be given in single quotes like this --
db.TestCollection.find('result.reference' : a3d245e343 }
I thought I can use double quotes in there but looks like I am wrong.
I was using a comma instead of a colon in the projector. The correct answer is -
db.TestCollection.find( {}, {"results.city" : 1} )