Working with Data - The Definitive Guide to MongoDB - page 55

"Released" : 1999,
"Cast" : [
"Keanu Reeves",
"Carrie-Anne Moss",
"Laurence Fishburne",
"Hugo Weaving",
"Gloria Foster",
"Joe Pantoliano"
]
}
> db.media.insert(dvd)
> dvd = ( { "Type" : "DVD", Title : "Blade Runner", Released : 1982 } )
{ "Type" : "DVD", "Title" : "Blade Runner", "Released" : 1982 }
> db.media.insert(dvd)
> dvd = ( { "Type" : "DVD", Title : "Toy Story 3", Released : 2010 } )
{ "Type" : "DVD", "Title" : "Toy Story 3", "Released" : 2010 }
> db.media.insert(dvd)
Performing Greater-Than and Less-Than Comparisons
You can use the following special parameters to perform greater-than and less-than comparisons in queries: $gt , $lt ,
$gte , and $lte . In this section, we'll look at how to use each of these parameters.
The first one we'll cover is the $gt (greater than) parameter. You can use this to specify that a certain integer
should be greater than a specified value in order to be returned:
> db.media.find ( { Released : {$gt : 2000} }, { "Cast" : 0 } )
{ "_id" : ObjectId("4c4369a3c603000000007ed3"), "Type" : "DVD", "Title" :
"Toy Story 3", "Released" : 2010 }
Note that the year 2000 itself will not be included in the preceding query. For that, you use the $gte (greater than
or equal to) parameter:
> db.media.find ( { Released : {$gte : 1999 } }, { "Cast" : 0 } )
{ "_id" : ObjectId("4c43694bc603000000007ed1"), "Type" : "DVD", "Title" :
"Matrix, The", "Released" : 1999 }
{ "_id" : ObjectId("4c4369a3c603000000007ed3"), "Type" : "DVD", "Title" :
"Toy Story 3", "Released" : 2010 }
Likewise, you can use the $lt (less than) parameter to find items in your collection that predate the year 1999:
> db.media.find ( { Released : {$lt : 1999 } }, { "Cast" : 0 } )
{ "_id" : ObjectId("4c436969c603000000007ed2"), "Type" : "DVD", "Title" : "Blade Runner",
"Released" : 1982 }