Query Method
MongoDB provides the db.collection.find() method to read documents from a collection. The db.collection.find() method returns a cursor to the matching documents.
db.collection.find( <query filter>, <projection> )
For the db.collection.find() method, you can specify the following optional fields:
- a query filter to specify which documents to return.
- a query projection to specifies which fields from the matching documents to return. The projection limits the amount of data that MongoDB returns to the client over the network.
You can optionally add a cursor modifier to impose limits, skips, and sort orders. The order of documents returned by a query is not defined unless you specify a sort().
Example Collection
The examples on this page use the db.collection.find() method in the mongo shell. In the mongoshell, if the returned cursor is not assigned to a variable using the var keyword, then the cursor is automatically iterated up to 20 times to print up to the first 20 documents in the results.
To populate the users collection referenced in the examples, run the following in mongo shell:
NOTE: If the users collection already contains documents with the same _id values, you need to drop the collection (db.users.drop()) before inserting the example documents.
db.users.insertMany(
[
{
_id: 1,
name: "sue",
age: 19,
type: 1,
status: "P",
favorites: { artist: "Picasso", food: "pizza" },
finished: [ 17, 3 ],
badges: [ "blue", "black" ],
points: [
{ points: 85, bonus: 20 },
{ points: 85, bonus: 10 }
]
},
{
_id: 2,
name: "bob",
age: 42,
type: 1,
status: "A",
favorites: { artist: "Miro", food: "meringue" },
finished: [ 11, 25 ],
badges: [ "green" ],
points: [
{ points: 85, bonus: 20 },
{ points: 64, bonus: 12 }
]
},
{
_id: 3,
name: "ahn",
age: 22,
type: 2,
status: "A",
favorites: { artist: "Cassatt", food: "cake" },
finished: [ 6 ],
badges: [ "blue", "red" ],
points: [
{ points: 81, bonus: 8 },
{ points: 55, bonus: 20 }
]
},
{
_id: 4,
name: "xi",
age: 34,
type: 2,
status: "D",
favorites: { artist: "Chagall", food: "chocolate" },
finished: [ 5, 11 ],
badges: [ "red", "black" ],
points: [
{ points: 53, bonus: 15 },
{ points: 51, bonus: 15 }
]
},
{
_id: 5,
name: "xyz",
age: 23,
type: 2,
status: "D",
favorites: { artist: "Noguchi", food: "nougat" },
finished: [ 14, 6 ],
badges: [ "orange" ],
points: [
{ points: 71, bonus: 20 }
]
},
{
_id: 6,
name: "abc",
age: 43,
type: 1,
status: "A",
favorites: { food: "pizza", artist: "Picasso" },
finished: [ 18, 12 ],
badges: [ "black", "blue" ],
points: [
{ points: 78, bonus: 8 },
{ points: 57, bonus: 7 }
]
}
]
)