Models

Sutando has data models built on top of the active record pattern .

The data models layer of Sutando makes it super easy to perform CRUD operations, manage relationships between models.

We recommend using models extensively and reach for the standard query builder for particular use cases.

Creating your first model

Let's examine a basic model class and discuss some of Sutando's key conventions:

const { Model } = require('sutando');

class Flight extends Model {
  //
}

Table Names

After glancing at the example above, you may have noticed that we did not tell Sutando which database table corresponds to our Flight model. By convention, the "snake case", plural name of the class will be used as the table name unless another name is explicitly specified. So, in this case, Sutando will assume the Flight model stores records in the flights table, while an AirTrafficController model would store records in an air_traffic_controllers table.

If your model's corresponding database table does not fit this convention, you may manually specify the model's table name by defining a table property on the model:

const { Model } = require('sutando');

class Flight extends Model {
  // The table associated with the model.
  table = 'my_flights';
}

Primary Keys

Sutando will also assume that each model's corresponding database table has a primary key column named id. If necessary, you may define a protected primaryKey property on your model to specify a different column that serves as your model's primary key:

const { Model } = require('sutando');

class Flight extends Model {
  // The primary key associated with the table.
  primaryKey = 'flight_id';
}

If you wish to use a non-incrementing or a non-numeric primary key you must define a incrementing property on your model that is set to false:

class Flight extends Model {
  // Indicates if the model's ID is auto-incrementing.
  incrementing = false;
}

If your model's primary key is not an integer, you should define a keyType property on your model. This property should have a value of string:

class Flight extends Model {
  // The data type of the auto-incrementing ID.
  keyType = 'string';
}

UUID & String Keys

You can choose to use a string instead of an auto-incrementing integer as the model's primary key. For example, use a UUID as the primary key by defining a newUniqueId method in the model:

npm

$ npm install uuid --save

yarn

$ yarn add uuid

pnpm

$ pnpm add uuid

const { Model, compose, HasUniqueIds } = require('sutando');
const uuid = require('uuid');

class Article extends compose(Model, HasUniqueIds) {
  newUniqueId() {
    return uuid.v4();
  }

  // ...
}

const article = await Article.create({
  title: 'Traveling to Europe'
});

article.id; // "8f8e8478-9035-4d23-b9a7-62f4d2612ce5"

Timestamps

By default, Sutando expects created_at and updated_at columns to exist on your model's corresponding database table. Sutando will automatically set these column's values when models are created or updated. If you do not want these columns to be automatically managed by Sutando, you should define a timestamps property on your model with a value of false:

const { Model } = require('sutando');

class Flight extends Model {
  // Indicates if the model should be timestamped.
  timestamps = false;
}

If you need to customize the names of the columns used to store the timestamps, you may set CREATED_AT and UPDATED_AT properties pro on your model:

const { Model } = require('sutando');

class Flight extends Model {
  static CREATED_AT = 'creation_date';
  static UPDATED_AT = 'updated_date';
}

Database Connections

By default, all Sutando models will use the default database connection that is configured for your application. If you would like to specify a different connection that should be used when interacting with a particular model, you should define a connection property on the model:

const { Model } = require('sutando');

class Flight extends Model {
  connection = 'sqlite';
}

Default Attribute Values

By default, a newly instantiated model instance will not contain any attribute values. If you would like to define the default values for some of your model's attributes, you may define an attributes property on your model. Attribute values placed in the attributes should be in their raw, "storable" format as if they were just read from the database:

const { Model } = require('sutando');

class Flight extends Model {
  attributes = {
    options: '[]',
    delayed: false,
  };
}

Retrieving Models

Once you have created a model and its associated database table, you are ready to start retrieving data from your database. You can think of each Sutando model as a powerful query builder allowing you to fluently query the database table associated with the model. The model's all method will retrieve all of the records from the model's associated database table:

const { Flight } = require('./models');

const flights = await Flight.query().all();

flights.map(flight => {
  console.log(flight.name)
})

Building Queries

The Sutando all method will return all of the results in the model's table. However, since each Sutando model serves as a query builder, you may add additional constraints to queries and then invoke the get/first/find method to retrieve the results:

const flights = await Flight.query().where('active', 1)
  .orderBy('name')
  .take(10)
  .get();

const flight = await Flight.query().where('active', 1).first();

const flight = await Flight.query().find(5);

Refreshing Models

If you already have an instance of an Sutando model that was retrieved from the database, you can "refresh" the model using the fresh and refresh methods. The fresh method will re-retrieve the model from the database. The existing model instance will not be affected:

const flight = await Flight.query().where('number', 'FR 900').first();
 
const freshFlight = await flight.fresh();

The refresh method will re-hydrate the existing model using fresh data from the database. In addition, all of its loaded relationships will be refreshed as well:

const flight = await Flight.query().where('number', 'FR 900').first();
 
flight.number = 'FR 456';
 
await flight.refresh();
 
flight.number; // "FR 900"

Collections

As we have seen, Sutando methods like all and get retrieve multiple records from the database. However, these methods don't return a plain array. Instead, an instance of Collection is returned.

The Sutando Collection class extends collect.js class, which provides a variety of helpful methods for interacting with data collections. For example, the reject method may be used to remove models from a collection based on the results of an invoked closure:

const flights = await Flight.query().where('destination', 'Paris').get();
 
const newFlights = flights.reject(flight => {
  return flight.cancelled;
});

In addition to the methods provided by collect.js's base collection class, the Sutando collection class provides a few extra methods that are specifically intended for interacting with collections of Sutando models.

Since all of Sutando collections implement Javascript's iterable interfaces, you may loop over collections as if they were an array:

for (let flight of flights) {
  console.log(flight.name);
}

Chunking Results

Your application may run out of memory if you attempt to load tens of thousands of Sutando records via the all or get methods. Instead of using these methods, the chunk method may be used to process large numbers of models more efficiently.

The chunk method will retrieve a subset of Sutando models, passing them to a closure for processing. Since only the current chunk of Sutando models is retrieved at a time, the chunk method will provide significantly reduced memory usage when working with a large number of models:

const { Flight } = require('./models');
 
await Flight.query().chunk(200, flights => {
  flights.map(flight => {
    //
  });
});

Retrieving Single Models / Aggregates

In addition to retrieving all of the records matching a given query, you may also retrieve single records using the find or first methods. Instead of returning a collection of models, these methods return a single model instance:

const { Flight } = require('./modles');
 
// Retrieve a model by its primary key...
const flight = await Flight.query().find(1);
 
// Retrieve the first model matching the query constraints...
const flight = await Flight.query().where('active', 1).first();

Not Found Errors

Sometimes you may wish to throw an exception if a model is not found. This is particularly useful in routes or controllers. The findOrFail and firstOrFail methods will retrieve the first result of the query; however, if no result is found, an ModelNotFoundError will be thrown:

const { ModelNotFoundError } = requre('sutando');

try {
  const flight = await Flight.query().findOrFail(1);
  const flight = await Flight.query().where('legs', '>', 3).firstOrFail();
} catch (e) {
  e instanceof ModelNotFoundError;
}

With the framework capturing ModelNotFoundError, a 404 HTTP response can be automatically sent back to the client:

const app = require('express')();
require('express-async-errors');
const { ModelNotFoundError } = requre('sutando');

app.get('/users/:id', async (req, res) => {
  const user = await User.query().findOrFail(req.params.id);

  res.send(user);
});

app.use((err, req, res, next) => {
  if (err instanceof ModelNotFoundError) {
    return res.status(404).send(err.message);
  }

  next(err);
});

Retrieving Or Creating Models

The firstOrCreate method will attempt to locate a database record using the given column / value pairs. If the model can not be found in the database, a record will be inserted with the attributes resulting from merging the first array argument with the optional second array argument:

The firstOrNew method, like firstOrCreate, will attempt to locate a record in the database matching the given attributes. However, if a model is not found, a new model instance will be returned. Note that the model returned by firstOrNew has not yet been persisted to the database. You will need to manually call the save method to persist it:

const { Flight } = require('./modles');
 
// Retrieve flight by name or create it if it doesn't exist...
const flight = await Flight.query().firstOrCreate({
  name: 'London to Paris'
});
 
// Retrieve flight by name or create it with the name, delayed, and arrival_time attributes...
const flight = await Flight.query().firstOrCreate(
  { name: 'London to Paris' },
  { delayed: 1, arrival_time: '11:30' }
);
 
// Retrieve flight by name or instantiate a new Flight instance...
const flight = await Flight.query().firstOrNew({
  name: 'London to Paris'
});
 
// Retrieve flight by name or instantiate with the name, delayed, and arrival_time attributes...
const flight = await Flight.query().firstOrNew(
  { name: 'Tokyo to Sydney' },
  { delayed: 1, arrival_time: '11:30' }
);

Retrieving Aggregates

When interacting with Sutando models, you may also use the count, sum, max, and other aggregate methods provided by the query builder. As you might expect, these methods return a scalar value instead of an Sutando model instance:

const count = await Flight.query().where('active', 1).count(); // 100
 
const max = await Flight.query().where('active', 1).max('price'); // 104

const flight = await Flight.query().find(1); // flight instanceof Flight

Inserting & Updating Models

Inserts

Of course, when using Sutando, we don't only need to retrieve models from the database. We also need to insert new records. Thankfully, Sutando makes it simple. To insert a new record into the database, you should instantiate a new model instance and set attributes on the model. Then, call the save method on the model instance:

// express
const { Flight } = require('./model');

app.post('/flights', async (req, res) => {
  // Validate the request...

  const flight = new Flight;
  flight.name = req.name;
  await flight.save();

  res.send(flight);
});

In this example, we assign the name field from the incoming HTTP request to the name attribute of the Flight model instance. When we call the save method, a record will be inserted into the database. The model's created_at and updated_at timestamps will automatically be set when the save method is called, so there is no need to set them manually.

Alternatively, you may use the create method to "save" a new model using a single PHP statement. The inserted model instance will be returned to you by the create method:

const { Flight } = require('./model');

const flight = await Flight.query().create({
  name: 'London to Paris',
});

Updates

The save method may also be used to update models that already exist in the database. To update a model, you should retrieve it and set any attributes you wish to update. Then, you should call the model's save method. Again, the updated_at timestamp will automatically be updated, so there is no need to manually set its value:

const { Flight } = require('./model');

const flight = await Flight.query().find(1);
flight.name = 'Paris to London';
await flight.save();

Mass Updates

Updates can also be performed against models that match a given query. In this example, all flights that are active and have a destination of San Diego will be marked as delayed:

await Flight.query().where('active', 1)
  .where('destination', 'San Diego')
  .update({
    delayed: 1,
  });

The update method expects an array of column and value pairs representing the columns that should be updated. The update method returns the number of affected rows.

TIP

When issuing a mass update, the saving, saved, updating, and updated model events will not be fired for the updated models. This is because the models are never actually retrieved when issuing a mass update.

Examining Attribute Changes

Sutando provides the isDirty methods to examine the internal state of your model and determine how its attributes have changed from when the model was originally retrieved.

The isDirty method determines if any of the model's attributes have been changed since the model was retrieved. You may pass a specific attribute name or an array of attributes to the isDirty method to determine if any of the attributes are "dirty". This method also accepts an optional attribute argument:

const { Flight } = require('./model');

const user = await User.query().create({
  first_name: 'Taylor',
  last_name: 'Otwell',
  title: 'Developer',
});
 
user.title = 'Painter';
 
user.isDirty(); // true
user.isDirty('title'); // true
user.isDirty('first_name'); // false
user.isDirty(['first_name', 'title']); // true
 
await user.save();
 
user.isDirty(); // false

Upserts

Occasionally, you may need to update an existing model or create a new model if no matching model exists. Like the firstOrCreate method, the updateOrCreate method persists the model, so there's no need to manually call the save method.

In the example below, if a flight exists with a departure location of Oakland and a destination location of San Diego, its price and discounted columns will be updated. If no such flight exists, a new flight will be created which has the attributes resulting from merging the first argument object with the second argument object:

const flight = await Flight.query().updateOrCreate(
  {
    departure: 'Oakland',
    destination: 'San Diego'
  },
  {
    price: 99,
    discounted: 1
  }
);

Deleting Models

To delete a model, you may call the delete method on the model instance:

const { Flight } = require('./models');

const flight = await Flight.query().find(1);
await flight.delete();

Deleting An Existing Model By Its Primary Key

In the example above, we are retrieving the model from the database before calling the delete method. However, if you know the primary key of the model, you may delete the model without explicitly retrieving it by calling the destroy method. In addition to accepting the single primary key, the destroy method will accept multiple primary keys, an array of primary keys, or a Collection of primary keys:

await Flight.query().destroy(1);
 
await Flight.query().destroy(1, 2, 3);
 
await Flight.query().destroy([1, 2, 3]);

Deleting Models Using Queries

Of course, you may build an Sutando query to delete all models matching your query's criteria. In this example, we will delete all flights that are marked as inactive. Like mass updates, mass deletes will not dispatch model events for the models that are deleted:

const deleted = await Flight.query().where('active', 0).delete();

Soft Deleting

In addition to actually removing records from your database, Sutando can also "soft delete" models. When models are soft deleted, they are not actually removed from your database. Instead, a deleted_at attribute is set on the model indicating the date and time at which the model was "deleted". To enable soft deletes for a model, use the SoftDeletes plugin and add the deleted_at field in the corresponding data table:

const { Model, compose, SoftDeletes } = require('sutando');

class Flight extends compose(Model, SoftDeletes) {
  // ...
}

Now, when you call the delete method on the model, the deleted_at column will be set to the current date and time. However, the model's database record will be left in the table. When querying a model that uses soft deletes, the soft deleted models will automatically be excluded from all query results.

To determine if a given model instance has been soft deleted, you may use the trashed method:

if (flight.trashed()) {
  //
}

Restoring Soft Deleted Models

Sometimes you may wish to "un-delete" a soft deleted model. To restore a soft deleted model, you may call the restore method on a model instance. The restore method will set the model's deleted_at column to null:

await flight.restore();

You may also use the restore method in a query to restore multiple models. Again, like other "mass" operations, this will not dispatch any model events for the models that are restored:

await Flight.query().withTrashed()
  .where('airline_id', 1)
  .restore();

The restore method may also be used when building relationship queries:

await flight.related('history').restore();

Permanently Deleting Models

Sometimes you may need to truly remove a model from your database. You may use the forceDelete method to permanently remove a model from the database table:

await flight.forceDelete();

You may also use the forceDelete method when building Sutando relationship queries:

await flight.related('history').forceDelete();

Querying Soft Deleted Models

Including Soft Deleted Models

As noted above, soft deleted models will automatically be excluded from query results. However, you may force soft deleted models to be included in a query's results by calling the withTrashed method on the query:

const { Flight } = require('./models');

const flights = await Flight.query().withTrashed()
  .where('account_id', 1)
  .get();

The withTrashed method may also be called when building a relationship query:

await flight.related('history').withTrashed().get();

Retrieving Only Soft Deleted Models

The onlyTrashed method will retrieve only soft deleted models:

const flights = await Flight.query().onlyTrashed()
  .where('airline_id', 1)
  .get();

Query Scopes

Scopes allow you to define common sets of query constraints that you may easily re-use throughout your application. For example, you may need to frequently retrieve all users that are considered "popular". To define a scope, prefix an Sutando model method with scope.

Scopes should always return the same query builder instance or void:

const { Model } = require('./models');

class User extends Model {
  scopePopular(query){
    return query.where('votes', '>', 100);
  }

  scopeActive(query){
    query.where('active', 1);
  }
}

Utilizing A Scope

Once the scope has been defined, you may call the scope methods when querying the model. However, you should not include the scope prefix when calling the method. You can even chain calls to various scopes:

const { User } = require('./models');

const users = await User.query().popular().active().orderBy('created_at').get();

Combining multiple Sutando model scopes via an or query operator may require the use of closures to achieve the correct logical grouping:

const users = await User.query().popular().orWhere(query => {
  query.active();
}).get();

Dynamic Scopes

Sometimes you may wish to define a scope that accepts parameters. To get started, just add your additional parameters to your scope method's signature. Scope parameters should be defined after the query parameter:

const { Model } = require('./models');

class User extends Model {
  scopeOfType(query, type){
    return query.where('type', type);
  }
}

Once the expected arguments have been added to your scope method's signature, you may pass the arguments when calling the scope:

const users = await User.query().ofType('admin').get();

Comparing Models

Sometimes you may need to determine if two models are the "same" or not. The is and isNot methods may be used to quickly verify two models have the same primary key, table, and database connection or not:

if (post.is(anotherPost)) {
  //
}
 
if (post.isNot(anotherPost)) {
  //
}