MongoDB documents
A document in MongoDB is a series of key-value pairs wrapped in curly braces.
MongoDB document example
{
"_id" : ObjectId("5c1d358bf383fbee028aea0b"),
"pet_name" : "Tom",
"pet_type" : "cat"
}
The structure of a MongoDB document follows JSON-like specification known as BSON.
Documents are grouped by collections in MongoDB, where each collection is equivalent to a table, and each document is equivalent to a row in a NoSQL database.
MongoDB subdocuments
A subdocument is a document within another document.
MongoDB subdocument example
{
"_id" : ObjectId("5c1d358bf383fbee028aea0b"),
"pet_name" : "Tom",
"pet_type" : "cat",
"pet_attributes": { // pet_attributes is a subdocument
"favorite_toy": "string",
"whisker_legth" "unknown"
}
}
pet_attributes
is a subdocument.
How to create a document in MongoDB
- Use the
insertOne()
method to insert one document. - Use the
insertMany()
method to insert more than one document.
insertOne() creates one document
db.items.insertOne(
{ "_id" : 1, "item" : "ABC", "price" : 10, "quantity" : 2, "expires" : new Date("01-05-2022")}
);
// db.items is the items collection
// insertOne() inserts a document in the items collection
insertMany() creates multiple documents
db.items.insertMany([
{ "_id" : 1, "item" : "ABC", "price" : 10, "quantity" : 2, "expires" : new Date("01-05-2022")},
{ "_id" : 2, "item" : "ZEF", "price" : 2, "quantity" : 54, "expires" : new Date("11-04-2022")},
]);