Models

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Like most MVC frameworks, Sails provides an ORM (Object Relational Mapping) called Waterline for normalizing interactions with models, no matter what data source you're using. It also defines an interface for mapping your own custom models from external APIs, not-yet-supported databases, or in-memory state (i.e. Session storage.)

What is a Model?

A model is a persistent data type: a representation of data stored in a database. If you're using MySQL, a model might correspond to a table. If you're using MongoDB, it might correspond to a collection. In either case, our goal is to provide a simple, modular way of managing data without relying on any one type of database.

How do I define a Model?

Model definitions contain attributes, validations, instance methods, lifecycle callbacks and class methods.

Attributes

Attributes are basic pieces of information about a model. For instance, a model called Person might have attribute called firstName, lastName, phoneNumber, age, birthDate and emailAddress. The model definition for Person might look like this:

// Person.js
var Person = {
  attributes: {
    firstName: 'STRING',
    lastName: 'STRING',
    age: {
      type: 'INTEGER',
      max: 150,
      required: true
    },
    birthDate: 'DATE',
    phoneNumber: {
      type: 'STRING',
      defaultsTo: '111-222-3333'
    },
    emailAddress: {
      type: 'email', // Email type will get validated by the ORM
      required: true
    }
  }
};

module.exports = Person;

Available Attribute Types:

The following attribute types are currently available:

string
text
integer
float
date
time
datetime
boolean
binary
array
json

To learn more about what methods are available to you, check out the waterline documentation.

Validations

Validations are defined on you attributes when defining a model. It uses Anchor behind the scenes to run validations whenever you create or update a record.

attributes: {
  name: {
    type: 'string',
    maxLength: 20,
    minLength: 5
  },

  email: {
    type: 'email',
    required: true
  }
}

Available validations are:

empty
required
notEmpty
undefined
string
alpha
numeric
alphanumeric
email
url
urlish
ip
ipv4
ipv6
creditcard
uuid
uuidv3
uuidv4
int
integer
number
finite
decimal
float
falsey
truthy
null
notNull
boolean
array
date
hexadecimal
hexColor
lowercase
uppercase
after
before
is
regex
not
notRegex
equals
contains
notContains
len
in
notIn
max
min
minLength
maxLength

Instance Methods

You can attach instance methods to a model which will be available on any record returned from a query. There are also a few helper instance methods that get attached to allow you to perform operations on a model instance without having to build the lookup criteria.

Helper Instance Methods:

save
destroy
toObject
toJSON

Save Instance Method

The save instance method will write the current values of the model instance to the datastore. It only takes a callback as it's argument.

// Lookup a user
User.findOne(1).done(function(err, user) {

  // we now have a model with instance methods attached
  // update an attribute value
  user.email = 'foo.bar@gmail.com';

  // save the updated value
  user.save(function(err) {
    // value has been saved
  });

});

Destroy Instance Method

The destroy instance method allows you to delete a single record from the datastore without having to build up a criteria search.

// Lookup a user
User.findOne(1).done(function(err, user) {

  // we now have a model with instance methods attached

  // destroy the record
  user.destroy(function(err) {
    // record has been removed
  });

});

toObject/toJSON Instance Methods

The toObject() method will return the currently set model values only, without any of the instance methods attached. Useful if you want to change or remove values before sending to the client.

However we provide an even easier way to filter values before returning to the client when using the blueprints by allowing you to override the toJSON() method in your model. This function will automatically be called when using the blueprints so you don't need to write custom controllers in order to filter values.

Example of filtering a password in your model definition:

module.exports = {
  attributes: {
    name: 'string',
    password: 'string',

    // Override toJSON instance method
    // to remove password value
    toJSON: function() {
      var obj = this.toObject();
      delete obj.password;
      return obj;
    }
  }
}

// Then later when you query it:

User.findOne(1).done(function(err, user) {
  // user.password doesn't exist
});

Custom Defined Instance Methods

You may define custom instance methods that are available after querying a model. These are defined as functions in your model attributes.

module.exports = {

  attributes: {
    firstName: 'string',
    lastName: 'string',

    // Define a custom instance method
    fullName: function() {
      return this.firstName + ' ' + this.lastName;
    }
  }
}

// Then use it in your query results like:
User.findOne(1).done(function(err, user) {
  // use the instance method
  var name = user.fullName();
});

Lifecycle Callbacks

Lifecycle callbacks are functions you can define to run at certain times in a query. They are hooks that you can tap into in order to change data. An example use case would be automatically encrypting a password before creating or automatically generating a slugified url attribute.

Callbacks run on Create:

- beforeValidation / *fn(values, cb)*
- beforeCreate / *fn(values, cb)*
- afterCreate / *fn(newlyInsertedRecord, cb)*

Callbacks run on Update:

- beforeValidation / *fn(valuesToUpdate, cb)*
- beforeUpdate / *fn(valuesToUpdate, cb)*
- afterUpdate / *fn(updatedRecord, cb)*

Callbacks run on Destroy:

- beforeDestroy / *fn(criteria, cb)*
- afterDestroy / *fn(cb)*

Examples

Encrypt a password before saving to the database.

var bcrypt = require('bcrypt');

module.exports = {
  
  attributes: {
    
    username: {
      type: 'string',
      required: true
    },
    
    password: {
      type: 'string',
      minLength: 6,
      required: true,
      columnName: 'encrypted_password'
    }
    
  },
  
  
  // Lifecycle Callbacks
  beforeCreate: function(values, next) {
    bcrypt.hash(values.password, 10, function(err, hash) {
      if(err) return next(err);
      values.password = hash;
      next();
    });
  }
};

Custom Table Names

You can define a custom table name on your adapter by adding a tableName attribute. If no table name is supplied it will use the filename as the table name when passing it to an adapter. So if your model's name is UserModel, the table name will be set to "user" by default.

// api/models/User.js
module.exports = {
  tableName: 'sails_user',
  attributes: {
    // attributes here
  }
};

Adapters

Adapters can be included from npm, or defined locally in the api/adapters directory of your project.

You can override the adapter globally for your application, or you can configure different models to point to different adapters. To see how to change your default application adapter config, check out the Configuration section of this documentation at Configuration

To override the adapter of a single model, you specify the adapter module's name and any extra configuration information necessary to make it work.

For example:

// api/models/User.js
module.exports = {

  adapter: 'mysql',

  config: {
    user: 'root',
    password: 'thePassword',
    database: 'testdb',
    host: '127.0.0.1'
  },

  attributes: {
    name: 'string',
    email: 'string',
    phoneNumber: {
      type: 'string',
      defaultsTo: '555-555-5555'
    }
  }

};

Our global is set to disk, however since we overrode the adapter our User models will now be stored in MySQL using the sails-mysql adapter.

Schemaless Mode

For adapters that don't require a schema such as Mongo or Redis the default setting is to be schemaless. This means that you don't need to specify attributes on your model in order to persist them. For some cases this may be fine but in other cases you would like to specify that all data sticks to a schema.

You can toggle the schema flag on models on or off. However note that if you are using a schema database such as MySQL or PostgreSQL you will not be able to use the model if schema is set to false.

module.exports = {
 
 adapter: 'mongo',
 schema: true,
 
 attributes: {
   // some attributes
 }
};

You may also set the schema flag globally in your config/adapters.js for a datastore. This will enable/disable a schema on all your models.

module.exports.adapters = {
  mongo: {
    module: 'sails-mongo',
    schema: true
  }
};

Associations

Associations are not yet available for Sails.JS, however are on the immediate todo list. Please check out issue #124 for more information regarding the proposed changes for associations.

Where do I define Models?

Models are defined in the api/models/ directory in your Sails application.

You can generate a model with the command line tool:

sails generate model Person

Automatic schema creation

Depending on your configuration, the database tables will be recreated automatically.

Querying Models

You'll want to create, access, modify, and destroy models from controllers, views, services, and policies, and so you'll need a way to deal with them.

Queries can be run with either a callback interface or with a deferred object. For building complicated queries the deferred object method is the best choice.

Callback Method

User.findOne({ id: 1 }, function(err, user) {
  // Do stuff here
});

Deferred Object Method

User.find()
.where({ id: { '>': 100 }})
.where({ age: 21 })
.limit(100)
.sort('name')
.exec(function(err, users) {
  // Do stuff here
});

`create`

To create a new record in the database, use create().

// For example
User.create({
  name: 'Mike',
  age: 13,
  phoneNumber: '(512)-555-5555'
}).done(function(err, user) {

  // Error handling
  if (err) {
    return console.log(err);

  // The User was created successfully!
  }else {
    console.log("User created:", user);
  }
});

`findOne`

To lookup a model by id, use findOne(id). You can call also look for a model by passing in an object composed of the desired matching criteria.

// For example to find by id
User.findOne(123).done(function(err, user) {

  // Error handling
  if (err) {
    return console.log(err);

  // The User was found successfully!
  } else {
    console.log("User found:", user);
  }
});


// To find by a criteria
User.findOne({
  name: 'Steven',
  age: 32,
  phone:'(210)-555-1234'
}).done(function(err, user) {

  // Error handling
  if (err) {
    return console.log(err);

  // The User was found successfully!
  } else {
    console.log("User found:", user);
  }
});

`find`

find() lets you search for one or more models which meet the criteria you specify. You can also include a limit (max number of models to return), skip (useful for pagination), and sort sort. Find all will always return an array even if only one model fits the criteria.

// For example, this query returns the first ten 18 year olds, sorted alphabetically
User.find({
  age: 18
}).limit(10).sort('name ASC').done(function(err, users) {

  // Error handling
  if (err) {
    return console.log(err);

  // Found multiple users!
  } else {
    console.log("Users found:", users);
  }
});

Below are some more examples. Some of these examples include query modifiers. You can view more about query modifiers here.

// Search-as-you-type input field
User.find({
  name: {
    startsWith: 'thelas'
  }
}, cb);

// Search-as-you-type input field which checks multiple attributes
User.find({
  or: [
    name: { startsWith: 'thelas' },
    email: { startsWith: 'thelas' }
  ]
}, cb);

// Keyword search
User.find({
  description: {
    contains: 'roller coaster'
  }
}, cb);

// Alphabetical search
User.find({
  name: {
    '>=': 'a'
  }
}, cb);
// you can also do <=, <, >, and ! See query modifiers

// Alphabetical search.. but paginated:
// (here's page 2)
User.find({
  where: {
    name: {
      '>=': 'a'
    }
  },
  limit: 15,
  skip: 15,
  sort: 'name ASC'
}, cb);

Dynamic finders

With Sails built in ORM, Waterline, you can use a very helpful tool called dynamic finders. You can query your models with automatically genereated methods that depend on the attributes you define for the model. For example, if you had a book model that looks like this.

var Book = {
  title: 'STRING',
  author: 'STRING',
  publisher: 'STRING',
}

module.exports = Book;

You can query the db using methods such as these

// Query by author
Book.findOneByTitle('50 Shades of Grey').done(function(err, book) {

  // Error handling
  if (err) {
    return console.log(err);

  // The Book was found successfully!
  } else {
    console.log("Book found:", book);
  }
});

// Query by Author
Book.findByAuthor('John R. Erickson').done(function(err, books) {

  // Error handling
  if (err) {
    return console.log(err);

  // The Books were found successfully!
  } else {
    console.log("Books found:", books);
  }
});

`update`

update() allows you to update an instance of a model from the database. It will always return an array of records that have been updated.

// For example, to update a user's name,
// .update(query, params to change, callback)
User.update({
  name: 'sally'
},{
  phone: '555-555-5555'
}, function(err, users) {
  // Error handling
  if (err) {
    return console.log(err);
  // Updated users successfully!
  } else {
    console.log("Users updated:", users);
  }
});

`destroy`

destroy() allows you to delete models from the database. It will work on all matching criteria.

// For example, to delete a user named Johnny,
User.destroy({
  name: 'Johnny',
  age: 22
}).done(function(err) {

  // Error handling
  if (err) {
    return console.log(err);

  // Johnny was deleted!
  } else {
    console.log("User deleted");
  }
});

Query Modifiers

Modifiers can be used in your database queries. These make it easier to get information from your database without having to write a bunch of code. Currently supported modifiers are contains, or, startsWith, endsWith, greaterThan, lessThan, >=, and <=. Each of these are shown in examples below.

Modifier: `contains`

In order to use a contains modifier, you would do the following.

where: {
  name: {
    contains: 'James'
  }
}

Modifier: `or`

In order to use an or modifier, you would do the following.

where: {
  or: [{name: 'James'}, {name: 'Mike'}]
}

What About Migrations?

In schemaful databases (like MySQL) schema migrations occur automatically. Models default to migrate:alter, which tells Sails to attempt to auto-migrate the schema.

Explicit production data migrations, like in Rails, do not exist at this time-- production data is precious, and manual migrations can be dangerous. However, if this is a feature that you are interested in, please submit an issue, or better yet, a pull-request!

More Information

For more information on using Models you can visit the Waterline documentation which goes more in depth on how the internals work.

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models.md

models.md

Models

What is a Model?

How do I define a Model?

Attributes

Available Attribute Types:

Validations

Instance Methods

Save Instance Method

Destroy Instance Method

toObject/toJSON Instance Methods

Custom Defined Instance Methods

Lifecycle Callbacks

Custom Table Names

Adapters

Schemaless Mode

Associations

Where do I define Models?

Automatic schema creation

Querying Models

Callback Method

Deferred Object Method

`create`

`findOne`

`find`

Dynamic finders

`update`

`destroy`

Query Modifiers

Modifier: `contains`

Modifier: `or`

What About Migrations?

More Information

Files

models.md

Latest commit

History

models.md

File metadata and controls

Models

What is a Model?

How do I define a Model?

Attributes

Available Attribute Types:

Validations

Instance Methods

Save Instance Method

Destroy Instance Method

toObject/toJSON Instance Methods

Custom Defined Instance Methods

Lifecycle Callbacks

Custom Table Names

Adapters

Schemaless Mode

Associations

Where do I define Models?

Automatic schema creation

Querying Models

Callback Method

Deferred Object Method

create

findOne

find

Dynamic finders

update

destroy

Query Modifiers

Modifier: contains

Modifier: or

What About Migrations?

More Information

`create`

`findOne`

`find`

`update`

`destroy`

Modifier: `contains`

Modifier: `or`