In order start adding collections and documents to our database, we use Mongoose's schema structure. This is specific to Mongoose and is not a structure that is a part of Mongo in general.
We use a schema to define the shape of documents in a MongoDB collection. To do this we instantiate an instance of the Mongoose `Schema` class and set our properties:
### Creating a schema
```js
const courseSchema = new mongoose.Schema({
name: String,
author: String,
tags: [String],
data: {type: Date, default: Date.now}, // if unspecified, entry will default to current date
isPublished: Boolean
});
```
This is just like defining an inteface or type within TypeScript.
#### Available data types
The following data types are available:
*`String`
*`Number`
*`Boolean`
*`Array`
*`Date`
*`Buffer`
*`ObjectID` (for UUIDs)
### Models
Once we have established our schema we can then create a **model** of it. A model is basically a class representation of the interface we define in the schema:
With this in place, we can then create instances of the model. This stands in relation to the model as an object does to a class:
```js
const course = new Course({
name: "Node.js Course",
author: "Ozzy Osbourne",
tags: ["node", "backend"],
isPublished: true
});
```
Having created a database, connected to it with Mongoose, and created a model we will see our collection reflected in Compass:
### Adding a document
We have our database (`playground`) and collection (`courses`) established. We now need to add documents to our collection. We will move our previous code into a function since this will be an asynchronous process:
