Delete Documents
On this page
Overview
The code snippets on this page demonstrate how to delete documents that are stored in a MongoDB collection. Delete operations use a query to specify which documents to delete.
Data Lake data sources do not support write operations.
Data Model
The examples on this page use a collection named store.items that
models various items available for purchase in an online store. Each
item has a name, an inventory quantity, and an array of customer
reviews.
// store.items { "_id": { "bsonType": "objectId" }, name: { "bsonType": "string" }, quantity: { "bsonType": "int" }, reviews: { "bsonType": "array", "items": { "username": { "bsonType": "string" }, "comment": { "bsonType": "string" } } } }
Snippet Setup
To use a code snippet in a function, you must first instantiate a MongoDB collection handle:
exports = function() { const mongodb = context.services.get("mongodb-atlas"); const itemsCollection = mongodb.db("store").collection("items"); const purchasesCollection = mongodb.db("store").collection("purchases"); // ... paste snippet here ... }
Methods
Delete a Single Document
You can delete a single document from a collection using the
collection.deleteOne() action.
The following function snippet deletes one document
in the items collection that has a name value of lego:
const query = { "name": "lego" }; itemsCollection.deleteOne(query) .then(result => console.log(`Deleted ${result.deletedCount} item.`)) .catch(err => console.error(`Delete failed with error: ${err}`))
Delete One or More Documents
You can delete multiple items from a collection using the
collection.deleteMany() action.
The following snippet deletes all documents in the items collection
that do not have any reviews:
const query = { "reviews": { "$size": 0 } }; itemsCollection.deleteMany(query) .then(result => console.log(`Deleted ${result.deletedCount} item(s).`)) .catch(err => console.error(`Delete failed with error: ${err}`))