Chapter 3. Creating, Updating, and Deleting Documents

This chapter covers the basics of moving data into and out of the database, including the following:

  • Adding new documents to a collection

  • Removing documents from a collection

  • Updating existing documents

  • Choosing the correct level of safety versus speed for all of these operations

Inserting Documents

Inserts are the basic method for adding data to MongoDB. To insert a single document, use the collection’s insertOne method:

> db.movies.insertOne({"title" : "Stand by Me"})

insertOne will add an "_id" key to the document (if you do not supply one) and store the document in MongoDB.

insertMany

If you need to insert multiple documents into a collection, you can use insertMany. This method enables you to pass an array of documents to the database. This is far more efficient because your code will not make a round trip to the database for each document inserted, but will insert them in bulk.

In the shell, you can try this out as follows:

> db.movies.drop()
true
> db.movies.insertMany([{"title" : "Ghostbusters"},
...                        {"title" : "E.T."},
...                        {"title" : "Blade Runner"}]);
{
      "acknowledged" : true,
       "insertedIds" : [
           ObjectId("572630ba11722fac4b6b4996"),
           ObjectId("572630ba11722fac4b6b4997"),
           ObjectId("572630ba11722fac4b6b4998")
       ]
}
> db.movies.find()
{ "_id" : ObjectId("572630ba11722fac4b6b4996"), "title" : "Ghostbusters" }
{ "_id" : ObjectId("572630ba11722fac4b6b4997"), "title" : "E.T." }
{ "_id" : ObjectId("572630ba11722fac4b6b4998"), "title" : "Blade ...

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