Schema
- Node.js course
- Advanced
- Lesson 26/83
- 5 min
Learn model schemas with Mongoose Schema.
The data blueprint
In Mongoose you define the data shape by creating a blueprint. This blueprint specifies which fields exist, their types (String, Number, Date), and validation rules. This keeps documents consistent.
The blueprint is written as a JavaScript object. For example { name: String, age: Number } defines two fields. Mongoose automatically builds a data structure from this definition. You cannot create a model without a blueprint; so the blueprint is the foundation of Mongoose.
Field types
Each field in a blueprint takes a type. Common types: String (text), Number (number), Date (date), Boolean (logical), Buffer (binary). The type determines how Mongoose stores and validates the document.
A type can also take options: { type: String, required: true, default: "name" }. required: true means the field cannot be empty; default gives a fallback value. This enforces data integrity at the application layer.
Practice Log the connection state
Import the mongoose module. Log mongoose.connection.readyState. (If not connected it is 0.)
Starter code
// import the module
// log the connection stateSample solution
const mongoose = require("mongoose");
console.log(mongoose.connection.readyState);Expected output
0
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Complete the module name
const mongoose = require("____")const mongoose = require("mongoose")Explanation: The Mongoose module loads as 'mongoose'.
2 What determines a field's type in a blueprint?
- A file name
- A JavaScript constructor (String, Number...) Correct answer
- A network connection
- A port number
Explanation: The type is given by JavaScript constructors like String, Number.
3 Match each piece to its role
| Term | Meaning |
|---|---|
String |
Text |
Number |
Number |
Date |
Date |
Boolean |
Logical |