In MongoDB the db.collection.updateMany() method updates all documents that match the specified filter for a collection.
Category: DBMS
Database Management Systems
MongoDB update()
In MongoDB the db.collection.update() method modifies an existing document or documents in a collection.
By default, it only updates a single document. But if multi: true is specified, then it updates all documents that match the query criteria.
MongoDB updateOne()
In MongoDB the db.collection.updateOne() method updates a single document within the collection based on the filter.
MongoDB insert()
In MongoDB the db.collection.insert() method inserts a document or documents into a collection.
The collection part is the name of the collection to insert the document/s into.
MongoDB insertMany()
In MongoDB the db.collection.insertMany() method inserts multiple documents into a collection.
The collection part is the name of the collection to insert the documents into.
MongoDB insertOne()
In MongoDB the db.collection.insertOne() method inserts a single document into a collection.
The collection part is the name of the collection to insert the document into.
2 Ways to Delete a Collection in MongoDB
If you no longer need a collection in MongoDB, you can delete it.
Actually, the term for deleting a collection is to drop the collection.
Either way, here are two ways to delete/drop a collection when using the mongo shell.
Continue reading4 Ways to List the Collections in a MongoDB Database
When using MongoDB, there’s more than one way to list the collections in a database.
Here are four ways to get a list of collections in a MongoDB database:
- The
show collectionsCommand - The
listCollectionsCommand - The
db.getCollectionNames()Method - The
db.getCollectionInfos()Method
MongoDB Upsert Explained
Many update operations in MongoDB have the potential to be upserts. An upsert is a combination of an insert and an update.
It works like this: You perform an update operation based on filter criteria, and if there are any matches, only the matched documents are updated, but if there are no matches, then a new document is inserted.
Continue readingCreate a Collection in MongoDB
When you create a database in MongoDB, your database is basically an empty container for which you can add one or more collections to.
A collection is analogous to a table in relational databases.
In relational databases, you can use CREATE TABLE to create each table that you want in the database.
But MongoDB is not a relational database, and it stores its data as documents. Each document is stored in a collection.
This article shows you how to create a collection in MongoDB.
Continue reading