Custom Postgresql Sequence Nextval in SequelizeJS

Question

How can i define sequence nextval() in sequelizeJS Model.

Is there any predefined function available for nextval() in sequelizeJS ?,

Is there any possiblity to write sequence nextval() custom function inside sequelize define model ?

Answer 1

Currently there is no way in sequelize to do so, kindly refer

https://github.com/sequelize/sequelize/issues/3555

Answer 2

No predefined function for that. But you can make use of raw query and get nextval like

sequelize.query("SELECT nextval('sequence')", { 
 type: collection.Sequelize.QueryTypes.SELECT 
});

Answer 3

In case there is someone at this point who wants to do this as well, the best way to do it I guess is using Sequelize.literal:

// on your model

const model = sequelize.define("model", {
  ...attributes,
  customSequence: {
    type: DataTypes.INTEGER,
    allowNull: false,
    defaultValue: sequelize.Sequelize.literal("nextval('custom_sequence')")
  },
})

// after create a migration for your new column

module.exports = {
  up: async (queryInterface, sequelize) => {
    await queryInterface.sequelize.query("CREATE SEQUENCE custom_sequence start 1020 increment 20",)

    await queryInterface.addColumn('table', 'customSequence', {
      type: DataTypes.INTEGER,
      allowNull: false,
      defaultValue: sequelize.Sequelize.literal("nextval('custom_sequence')")
    })
  },

  down: async (queryInterface, sequelize) => {
    await queryInterface.sequelize.query('DROP SEQUENCE custom_sequence')
    await queryInterface.removeColumn('table', 'customSequence')
  }
};