Working with Data - MongoDB Basics - page 60

{
"Track" : "2",
"Title" : "In Bloom",
"Length" : "4:15"
}
] }
Using a period [ . ] after the key's name tells your find function to look for
information embedded in your documents. Things are a little simpler when working with
arrays. For example, you can execute the following query if you want to find a list of topics
written by Peter Membrey:
> db.media.find( { "Author" : "Membrey, Peter" } )
{ "_id" : "ObjectId("4c1a8a56c603000000007ecb"), "Type" : "Book", "Title" :
"Definitive Guide to MongoDB 2nd ed., The", "ISBN" : "978-1-4302-5821-6",
"Publisher" :
"Apress", "Author" : ["Hows, David ", "Plugge, Eelco", "Membrey, Peter",
"Hawkins, Tim"] }
However, the following command will not match any documents, even though it
might appear identical to the earlier track list query:
> db.media.find ( { "Tracklist" : {"Track" : "1" }} )
Subobjects must match exactly; therefore, the preceding query would only match a
document that contains no other information, such as Track.Title :
{"Type" : "CD",
"Artist" : "Nirvana"
"Title" : "Nevermind",
"Tracklist" : [
{
"Track" : "1",
},
{
"Track" : "2",
"Title" : "In Bloom",
"Length" : "4:15"
}
]
}