MongoDB mongosh Update

Update Document

To update an existing document we can use the updateOne() or updateMany() methods.

The first parameter is a query object to define which document or documents should be updated.

The second parameter is an object defining the updated data.

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updateOne()

The updateOne() method will update the first document that is found matching the provided query.

Let’s see what the “like” count for the post with the title of “Post Title 1”:

Example

db.posts.find( { title: "Post Title 1" } ) 

Now let’s update the “likes” on this post to 2. To do this, we need to use the $set operator.

Example

db.posts.updateOne( { title: "Post Title 1" }, { $set: { likes: 2 } } ) 

Check the document again and you’ll see that the “like” have been updated.

Example

db.posts.find( { title: "Post Title 1" } ) 

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Insert if not found

If you would like to insert the document if it is not found, you can use the upsert option.

Example

Update the document, but if not found insert it:

db.posts.updateOne( 
  { title: "Post Title 5" }, 
  {
    $set: 
      {
        title: "Post Title 5",
        body: "Body of post.",
        category: "Event",
        likes: 5,
        tags: ["news", "events"],
        date: Date()
      }
  }, 
  { upsert: true }
)

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updateMany()

The updateMany() method will update all documents that match the provided query.

Example

Update likes on all documents by 1. For this we will use the $inc (increment) operator:

db.posts.updateMany({}, { $inc: { likes: 1 } })