Update Data in MongoDB
Overview
In this guide, you will update a field in a document.
Time required: 10 minutes
What You'll Need
- A connection string to your MongoDB deployment.
- Sample datasets loaded into your cluster.
- An installed MongoDB Driver.
- Data inserted from Insert Data into MongoDB.
Procedure
Connect to your MongoDB instance.
Get the database and collection.
Switch to the database and collection you wish to work with. In
this case you will be using the sample_guides database and
comets collection.
Update all documents in the comets collection.
In the previous guide, you inserted
documents into the comets collection. Now, you have a
requirement to update those documents. All fields are in metric
units except for the radius, which is in imperial.
The following example uses an update document to convert
the radius field from the metric system to the imperial system
in all documents.
1 mile = 1.60934 kilometers
Display your results.
Many write operations in MongoDB return a result object that contains information about the operation.
For update operations, the result object will contain the modified count of documents the driver successfully updated. Here, you access this property and print them.
Check your results.
Here is the complete code followed by sample output.
Summary
If you have completed this guide, you have updated data in MongoDB.
In the next guide, you will delete documents from MongoDB.
See Also
See the following resources for more in-depth information about the concepts presented here:
Specify which documents to delete from MongoDB.