Alter table modify enum in Knex js for Postgresql gives error

Question

I am using knex js and postgresql database. I have used a migration file to create a table knex migrate:make create_car_table. In this I have added a column fuel_ty

Answer 1

You first need to drop the existing constraint, and create a new one with the new values. The code sample below should help.

exports.up = function(knex, Promise) {
  return knex.schema.raw(`
    ALTER TABLE "car" DROP CONSTRAINT "car_fuel_type_check";
    ALTER TABLE "car" ADD CONSTRAINT "car_fuel_type_check" CHECK (fuel_type IN ('HYBRID'::text, 'ELECTRIC'::text, 'PETROL'::text, 'DIESEL'::text))
  `);
};

// The reverse migration is similar
exports.down = function(knex, Promise) {
  return knex.schema.raw(`
    ALTER TABLE "car" DROP CONSTRAINT "car_fuel_type_check";
    ALTER TABLE "car" ADD CONSTRAINT "car_fuel_type_check" CHECK (fuel_type IN ('PETROL'::text, 'DIESEL'::text, 'CNG'::text));
  `);
};

I'm assuming your constraint name is car_fuel_type_check. If not, you should replace car_fuel_type_check with your constraint name.