MongoDB

• mongoDB database structured data as documents. (similar to JSON objects)
• Documents correspond to objects in code.
• Hierarchy of the MongoDB
  • DataBase
  • Collection
  • Document

Document Model

• mongoDB documents are displayed in JSON format but they store in BSON.
  • compare to JSON BSON are supported additional data types.

Object IDs

• A data type that can be used to create a unique id for the required id filed.

• All the documents need to have a object id.

• MongoDB support polymorphic data.

Data Modeling - Mongo Connecting to a MongoDB Database

MongoDB CRUD Operations

• Replaced a single document by using db.collection.replaceOne()
• Updated a field value by using the $set update operator in db.collection.updateOne().
• Added a value to an array by using the $push update operator in db.collection.updateOne().
• Added a new field value to a document by using the upsert option in db.collection.updateOne().
• Found and modified a document by using db.collection.findAndModify().
• Updated multiple documents by using db.collection.updateMany().
• Deleted a document by using db.collection.deleteOne().
• insertOne()
  • db.collection.insertOne()

MongoDB CRUD Operations: Modifying Query Results

In this unit, you learned how to modify query results with MongoDB. Specifically, you learned how to:

• Return query results in a specified order by using cursor.sort().

• Constrained the number of results returned by using cursor.limit().

• Specified fields to return by adding a projection document parameter in calls to db.collection.find().

• Counted the number of documents that match a query by using db.collection.countDocuments().