Validations and Migrations

Validations

Sequelize has a bunch of validations we can add to our models to ensure that our data has met certain criteria before add it to our database. To include validations in your model, wrap them in a validate object. An examples of this is validating an email address (making sure it has a @ etc. as well as ensuring that it is never null):

Read more about diffrent types of validations

models/user.js

module.exports = function(sequelize, DataTypes) {
  var user = sequelize.define("user", {

    email: {
      type: DataTypes.STRING,
      validate: {
        isEmail: true
       }
    },
  },

    {
    classMethods: {
      associate: function(models) {
        // associations can be defined here
      }
    }
  });

  return user;
};

Migrations

sequelize migration:create --name migrationNameGoesHere

This command creates a migration file, which is empty by default. You must specify the type of migration for both up and down methods. The up method is the migration you want to run, while the down method is the reverse.

For example, if I add a column in up, I would also want to remove that same column in down.

Migration Functions: http://docs.sequelizejs.com/en/latest/docs/migrations/#functions

Running a migration

Whenever we generate a migration, we have to run the migration to execute the up method (which we have in our migration - when we undo a migration we run the down method). To run the up method, run in terminal sequelize db:migrate. For the down method, run sequelize db:migrate:undo.

NOTE: When creating your own migrations, you should specify actions for both up and down methods. Otherwise, running the down method will not revert your migration.

Migration Documentation