Add “ON DELETE CASCADE” to existing column in Laravel

Question

I have user_id fk column in my table

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

I should add on cascade

Answer 1

Use the unsigned function to user_id in the present migration:

$table->interger('user_id')->unsigned();
$table->foreign('user_id')->references('id')->on('table_name')->onDelete('cascade');

Answer 2

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

I am assuming you used Illuminate\Database\Schema\Blueprint::primary() to create users.id. If that is the case, then users.id will be unsigned. Therefore your foreign key column user_id must also be unsigned.

Answer 3

Drop foreign key first. Thanks to Razor for this tip

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

Answer 4

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

Answer 5

In my case, i'll need to put the col name in an array else that will be an error.

Schema::table('transactions', function (Blueprint $table) {
    $table->dropForeign(['transactions_order_id_foreign']);
    $table->foreign('order_id')
        ->references('id')->on('orders')
        ->onDelete('cascade')
        ->change();
});

mysql 5.7 ver

Answer 6

Thanks for question answer. Help me get to this working code in L5.1 :

public function up()
{
    Schema::table('transactions', function (Blueprint $table) {
        $table->dropForeign('transactions_order_id_foreign');
        $table->foreign('order_id')
            ->references('id')->on('orders')
            ->onDelete('cascade')
            ->change();
    });

    Schema::table('orders', function (Blueprint $table) {
        $table->dropForeign('orders_user_id_foreign');
        $table->foreign('user_id')
            ->references('id')->on('users')
            ->onDelete('cascade')
            ->change();
    });
}