How to drop foreign key in laravel migration ?

Drop foreign key to existing table are easy as creating a foreign key and adding columns to it. In laravel migration we can drop foreign key in laravel migration to existing table using dropForeign method of migration class. Major difference between creating new table and updating new table is Schema::create and Schema::table In this tutorial we will create a new migration file and then will drop foreign key column user_id to the existing table .

I hope you know about How to make database connection in Laravel 8 ?

We will use the php artisan command to generate the drop foreign key in laravel migration and php artisan migrate command to modify the table.

I am assuming that you have already table movies and user_id column with foreign key in database and now we are deleting foreign key.

Also you can read How to add column in laravel migration ?

Steps to drop foreign key in laravel migration

Let’s understand the drop foreign key in laravel migration step by step

Step 1 : Generate migration file

To generate the migration file we will use the laravel artisan command so open the terminal in project and run below command

php artisan make:migration DeleteForeignUserIdMoviesTable

Above command will create a migration file in folder database/migrations

Output: 
Created Migration: 2022_02_17_172323_delete_foreign_user_id_movies_table

Step 2 : Open generated migration file and update

In the last step we created a migration file using the artisan command and now we wanted to drop foreign keyto schema of movies table.

so let’s open the file and start editing

<?php

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

class DeleteForeignUserIdMoviesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        //
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        //
    }
}

In the file there is a class named as DeleteForeignUserIdMoviesTable and it extends Migration class. DeleteForeignUserIdMoviesTable class contains two methods one is up and other one is down.

Up is used to update the database scheme and down method is used to rollback the changes of this migration. As you can see we are creating table movies in up method and dropping the table in down method.

let’s add remove the foreign key using dropForeign method from our table before updating the database.

 public function up()
 {
        Schema::table('movies', function (Blueprint $table) {
            
            $table->dropForeign(['user_id', 'another_column']);
        });
 }
 public function down()
 {
        Schema::table('movies', function (Blueprint $table) {
              $table->integer('user_id');
        });
 }

Here we used Schema::table to update the table.

Step 3 : Run Migration

In this step we will execute our migration in database using below command

php artisan migrate

This will create table in database and the output

Output: 
Migrating: 2022_02_17_172323_delete_foreign_user_id_movies_table
Migrated:  2022_02_17_172323_delete_foreign_user_id_movies_table (27.20ms)

Screenshot After:

Also Read : How to add column in laravel migration ?