Deleting Documents in Node.js Applications

Review the following code, which demonstrates how to delete documents in MongoDB with Node.js.

Using deleteOne()

To delete a single document from a collection, use the deleteOne() method on a collection object. This method accepts a query filter that matches the document that you want to delete. If you do not specify a filter, MongoDB matches and deletes the first document in the collection. Here's an example:

const dbname = "bank"
const collection_name = "accounts"

const accountsCollection = client.db(dbname).collection(collection_name)

const documentToDelete = { _id: ObjectId("62d6e04ecab6d8e13049749c") }

const main = async () => {
  try {
    await connectToDatabase()
    let result = await accountsCollection.deleteOne(documentToDelete)
    result.deletedCount === 1
      ? console.log("Deleted one document")
      : console.log("No documents deleted")
  } catch (err) {
    console.error(`Error deleting documents: ${err}`)
  } finally {
    await client.close()
  }
}

main()

Using deleteMany()

You can delete multiple documents from a collection in a single operation by calling the deleteMany() method on a collection object. To specify which documents to delete, pass a query filter that matches the documents that you want to delete. If you provide an empty document, MongoDB matches all documents in the collection and deletes them. In the following example, we delete all accounts with a balance of less than 500 by using a query filter. Then, we print the total number of deleted documents.

const dbname = "bank"
const collection_name = "accounts"

const accountsCollection = client.db(dbname).collection(collection_name)

const documentsToDelete = { balance: { $lt: 500 } }

const main = async () => {
 try {
   await connectToDatabase()
   let result = await accountsCollection.deleteMany(documentsToDelete)
   result.deletedCount > 0
     ? console.log(`Deleted ${result.deletedCount} documents`)
     : console.log("No documents deleted")
 } catch (err) {
   console.error(`Error deleting documents: ${err}`)
 } finally {
   await client.close()
 }
}
 
main()