Interacting with the Database

Summary

In this lesson, we explored how to interact with a Waterline model using the Sails console. The Sails console is a Node.js REPL that loads your Sails application, giving access to models, helpers, and configurations.

Key points covered:

Starting the Sails console: Run sails console in the terminal to launch an interactive environment with Sails loaded.
Migration strategies: Sails warns about migration strategies when models are defined. Options include:
- alter (recommended for development)
- drop (for testing, clears data on every start)
- safe (for production, prevents automatic migrations)
Running the console without lifting the app: Use sails console --dontLift to avoid occupying the app’s port.
Checking the Sails instance: Running Sails in the console provides an overview of models, hooks, and app details.
Creating a model entry: Use Article.create({...}).log() to add a new article.
Fetching results: Append .fetch() to create() to return the newly created record.
Retrieving records:
- Article.find().log() returns all records.
- Article.findOne(2).log() retrieves a single record by ID.
- The long-form query Article.findOne({ id: 2 }).log() achieves the same result.

In the next lesson, we’ll use these queries to return all articles dynamically.

Transcript

Hello there! In the previous lesson, we created our first Waterline model, the Article model. Now, we'll interact with it using the Sails console, a REPL (Read-Evaluate-Print Loop) that loads our Sails application and gives us access to models, helpers, and configurations.

Starting the Sails console

To launch the console, ensure you're inside your Sails project directory (blog in our case) and run:

sails console

This starts an interactive session with Sails. However, you might see a warning about migration strategies if you haven’t set one.

Understanding migration strategies

Sails requires a migration strategy to handle model changes:

alter – Preserves data while updating table structure (recommended for development).
drop – Clears all tables on every start (useful for testing).
safe – No automatic migrations (ideal for production).

To set the migration strategy, update config/models.js:

migrate: 'alter'

Restart the Sails console for changes to take effect:

sails console

Running the console without lifting the app

By default, the Sails console also starts the app, meaning localhost:1337 remains active. If you want to run the console without lifting the app, use:

sails console --dontLift

Now, the app won’t occupy the port.

Checking the Sails instance

Inside the console, running:

sails

displays details like the number of models, hooks, and configurations loaded.

Creating an article

To create a new article, use:

Article.create({
  title: 'Hello Sails',
  body: 'This is my very first interaction with the Sails model.'
}).log();

This logs the creation process but doesn’t return the inserted record. To retrieve the newly created entry, use .fetch():

Article.create({
  title: 'Another New Article',
  body: 'New article body'
}).fetch().log();

Fetching records

To retrieve all articles:

Article.find().log();

This returns an array of all articles, including automatically added fields like createdAt, updatedAt, and id.

To get a specific article by ID:

Article.findOne(2).log();

Alternatively, you can use the long-form syntax:

Article.findOne({ id: 2 }).log();

Both return a single object instead of an array.

Conclusion

Now we’ve seen how to create and retrieve records using the Sails console. In the next lesson, we’ll use these queries to dynamically return all articles in our application.

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