The MongoDB Database Tools include a utility called mongoexport that enables you to export MongoDB data to a CSV or JSON file.
This article shows you how to use mongoexport to export a MongoDB collection to a CSV file.
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How to Convert a MongoDB View to a Collection
If you have a view in a MongoDB database that you’d prefer to be a collection, you’re in the right place.
Below is an example of converting a view to a collection in MongoDB.
Copy/Clone a Database in MongoDB
In earlier versions of MongoDB, you could use the copyDB command or its helper method, db.copyDatabase() to copy a database.
MongoDB has since deprecated these. Also, starting in version 4.2, MongoDB has removed the copydb command, and therefore also the db.copyDatabase() method, which means that you can’t use them even if you wanted to if you’re using MongoDB 4.2 or later.
Fortunately, there’s another way to copy a MongoDB database.
Copy/Clone a Collection in MongoDB
In earlier versions of MongoDB, you could use the db.collection.copyTo() method to copy a collection.
MongoDB has since deprecated that method. Also, starting in version 4.2, MongoDB has removed the eval command. Given db.collection.copyTo() wraps eval, this means that you can’t use either of them if you’re using MongoDB 4.2 or later.
Fortunately, there’s another way to copy a MongoDB collection.
Restore a MongoDB Database using mongorestore
If you’ve backed up a database using the mongodump utility, you can restore it using the mongorestore utility.
The mongorestore utility loads data from either a binary database dump created by mongodump or the standard input into a mongod or mongos instance.
Back Up a MongoDB Database using mongodump
There are several ways to back up a database in MongoDB. One quick way to back up a database is to use the mongodump tool.
mongodump reads data from a MongoDB database and creates high fidelity BSON files which the mongorestore utitlity can use to restore a MongoDB database.
With mongodump, you can back up a collection, a database, or all databases.
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.
4 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.
Create 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.