Mongoose is an Object Data Modeling (ODM) library for MongoDB that provides structured schemas for defining data models in Node.js applications. The core purpose of Mongoose is to establish an abstraction layer between MongoDB and Node.js, allowing developers to use schemas to define document structures, data types, validation rules, and default values.
Key advantages of Mongoose include:
- Schema Definition: Define document structures through Schema, including field types, default values, validation rules, etc.
- Data Validation: Automatically validate data format and integrity before saving
- Middleware and Hooks: Support pre and post hooks to execute custom logic before/after operations
- Query Builder: Provide chainable query API to simplify MongoDB query operations
- Type Casting: Automatically handle data type conversions, such as string to number
- Virtual Fields: Define computed fields that are not stored in the database
- Instance Methods: Add custom methods to model instances
- Static Methods: Add custom methods to model classes
Mongoose workflow:
- Define Schema
- Create Model
- Instantiate Document
- Execute CRUD operations
Differences between Mongoose and native MongoDB driver:
- Mongoose provides type safety and validation, native driver does not
- Mongoose enforces structure with Schema, native driver is more flexible
- Mongoose has richer query API and middleware support
- Mongoose has a slightly steeper learning curve but higher development efficiency