How to add index to an existing column in Laravel

If you want to add a new index to some columns in your existing table, you can do it pretty easily with Laravel migration. First, create the migration:

php artisan make:migration "Add index to a column in categories table" --table=categories

Then edit the migration php file. In this example, we are adding two indexes to a table, parent_id and slug:

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('categories', function (Blueprint $table) {
            $table->index(['parent_id', 'slug']);
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('categories', function (Blueprint $table) {
            //
        });
    }
};