Database
NoSQL
MongoDB
Data Model
MongoDB Datatypes

MongoDB - Data Types

Introduction

MongoDB is a NoSQL database that stores data in a flexible, JSON-like format called BSON (Binary JSON). BSON extends the JSON model to provide additional data types, allowing for more expressive data representation. Understanding MongoDB's data types is essential for efficient data modeling and manipulation. This article covers the various data types in MongoDB, their uses, and how they can help you structure your data effectively.

Data Types in MongoDB

MongoDB supports a wide range of data types, making it versatile for different kinds of applications. Below is a detailed overview of the key data types used in MongoDB:

String

  • Description: Strings are the most commonly used data type in MongoDB. They store textual data and must be UTF-8 valid.
  • Usage: Ideal for storing names, descriptions, addresses, and any other textual information.
  { "name": "John Doe" }

Integer

  • Description: Used to store numerical values. Integers in MongoDB can be either 32-bit or 64-bit, depending on your server’s configuration.
  • Usage: Suitable for counting items, storing age, quantities, or any other whole numbers.
{ "age": 30 }

Boolean

  • Description: Stores Boolean values, true or false.
  • Usage: Commonly used for flags, status indicators, or any binary state.
{ "isActive": true }

Double

  • Description: Used for storing floating-point numbers.
  • Usage: Ideal for prices, measurements, and other values that require decimal points.
{ "price": 19.99 }

Min/Max Keys

  • Description: Special types used internally by MongoDB to compare a value against the lowest (MinKey) and highest (MaxKey) BSON elements.
  • Usage: Mostly used in complex queries or database internal operations.
{ "minValue": { "$minKey": 1 }, "maxValue": { "$maxKey": 1 } }

Arrays

  • Description: Arrays are used to store multiple values in a single key, allowing for a list-like structure.
  • Usage: Useful for storing lists, tags, and other collections of data within a document.
{ "tags": ["mongodb", "database", "NoSQL"] }

Timestamp

  • Description: A special BSON type used for storing timestamp values.
  • Usage: Useful for tracking the creation, modification, or access times of a document.
{ "createdAt": { "$timestamp": { "t": 1628795627, "i": 1 } } }
  • t (seconds): Represents the number of seconds since the UNIX epoch (January 1, 1970).
  • i (increment): A counter that differentiates multiple timestamp values generated within the same second.

Object

  • Description: Used to store embedded documents, allowing for nested structures within a document.
  • Usage: Ideal for representing relationships and hierarchies in a single document.
{ 
  "user": { 
    "name": "Jane Doe", 
    "contact": { "email": "jane.doe@example.com", "phone": "123-456-7890" } 
  }
}

Null

  • Description: Stores a null value, indicating an absence of data.
  • Usage: Useful for fields where data is optional or unknown.
{ "middleName": null }

Date

  • Description: Stores dates and times in UNIX time format (milliseconds since January 1, 1970).
  • Usage: Used for logging events, timestamps, or any date-time-related data.
{ "lastLogin": { "$date": "2024-09-07T10:00:00Z" } }

Object ID

  • Description: A unique identifier for each document, automatically generated by MongoDB.
  • Usage: Serves as the primary key for documents, ensuring each document is uniquely identifiable.
{ "_id": "64f78e0cd3b5f5c7b9a1c9d4" }

Binary Data

  • Description: Used to store binary data, such as images, files, or any other binary format.
  • Usage: Ideal for applications that need to store multimedia or large binary objects.
{ "profilePicture": { "$binary": { "base64": "c29tZUJhc2U2NEJpbmFyeURhdGE=", "subType": "00" } } }

Code

  • Description: Stores JavaScript code directly within the document.
  • Usage: Useful for server-side logic or storing scripts related to the data.
{ "validation": { "$code": "function() { return this.age > 18; }" } }

Regular Expression

  • Description: Used to store regular expressions, allowing pattern matching and string searching directly in queries.
  • Usage: Helpful for filtering data based on patterns.
{ "pattern": { "$regex": "^start" } }

UUID

  • Description: Universally Unique Identifier used for globally unique identifiers.
  • Usage: Ideal for applications requiring unique IDs across distributed systems.
{ "uniqueId": { "$uuid": "550e8400-e29b-41d4-a716-446655440000" } }

Conclusion

MongoDB's wide range of data types offers flexibility and versatility for data storage. From simple types like strings and integers to complex structures like objects and arrays, MongoDB's data types help cater to various application needs. Understanding these types and their appropriate use cases will enable you to design robust, efficient, and scalable MongoDB applications.

Database, Collections and Documents in MongoDBJSON and BSON