Answers for "laravel migration constraint foreign key"

foreign key in laravel migration

$table->unsignedBigInteger('user_id');
$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

laravel foreign key

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});
OR
Schema::table('posts', function (Blueprint $table) {
    $table->foreignId('user_id')->constrained();
});

laravel 8 foreign key migration

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

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

    $table->foreign('user_id')->references('id')->on('users');
});

laravel foreign key constraint

public function up()
{
    Schema::create('replies', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->text('body');
        $table->unsignedBigInteger('question_id');
        $table->integer('user_id')->unsigned();
        $table->foreign('question_id')->references('id')->on('questions')->onDelete('cascade');
        $table->timestamps();
    });
}

laravel change foreign key name

//Note : Before Renaming Foreign, You Must Need To Delete Old Foreign And Assign New One
class RenameColumn extends Migration
{

    public function up()
    {
        Schema::table('holidays', function(Blueprint $table) {
            $table->dropForeign('holidays_account_id_foreign');
            $table->renameColumn('account_id ', 'engagement_id');

            $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
        });
    }

    public function down()
    {
        Schema::table('holidays', function(Blueprint $table) {
            $table->dropForeign('holidays_engagement_id_foreign');
            $table->renameColumn('account_id ', 'engagement_id');

            $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
        });
    }
}