Basics

The views support try to be the more transparent and squelize-styled as possible.

Define new View

To create a new View, you need to use a familiar syntax, as a normal Model, with the difference that you need to define the select query the view must to create.

There are two ways for it; Using an option called viewQueryOptions or override a static method called getQueryOptions.

Using config:

The easy way is pass the query options by init options, ex:

class EnabledUser extends View {}

EnabledUser.init({
  username: DataTypes.STRING,
  enabled: DataTypes.BOOLEAN,
}, {
  sequelize,
  timestamps: false,
  viewQueryOptions: {
    model: User,
    attributes: ['id', 'username'],
    where: {
      enabled: true,
    },
  },
});

Using it we are creating a view using info from model User, using a similar syntax to do a findAll.

Overriding getQueryOptions

The other way is overriding the static method getQueryOptions, this gets as first param the options of the View (as a model):

class EnabledUser extends View {
  static getQueryOptions(options) {
    return {
      model: User,
      attributes: ['id', 'username'],
      where: {
        enabled: true,
      },
    };
  }
}

EnabledUser.init({
  username: DataTypes.STRING,
  enabled: DataTypes.BOOLEAN,
}, {
  sequelize,
  timestamps: false,
});

Using both

You can to override the method using the previous viewQueryOptions option, ex:

class EnabledUser extends View {
  static getQueryOptions(options) {
    return {
      model: User,
      attributes: ['id', 'username'],
      ...options.viewQueryOptions,
    };
  }
}

EnabledUser.init({
  username: DataTypes.STRING,
  enabled: DataTypes.BOOLEAN,
}, {
  sequelize,
  timestamps: false,
  viewQueryOptions: {
    where: { enabled: true },
  },
});

Usage

The usage of a defined view is totally similar to use a standar model, using the View defined below, we can do:

const result = await EnabledUser.findAll();
console.log(result.map((user) => user.toJSON()));

The query options are applicable over the View, for example:

const result = await EnabledUser.findAll({
  attributes: ['username'],
  order: [
    ['username', 'DESC'],
  ],
});

All the supported methods by Sequelize.Model are supported, like findOne, count, etc.