Add "ON DELETE CASCADE" to existing column in Laravel
PhpLaravelLaravel 4Database MigrationPhp Problem Overview
I have user_id fk column in my table
$table->foreign('user_id')->references('id')->on('users');
I should add on cascade delete feature to this existing column. How can I do this?
Php Solutions
Solution 1 - Php
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');
Solution 2 - Php
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
Solution 3 - Php
$table->foreign('user_id')
->references('id')->on('users')
->onDelete('cascade');
Solution 4 - Php
Laravel schema builder can't modify columns at the current state, so you will use raw queries. You will have to drop and recreate the constraint:
PostgreSQL
function up()
{
DB::statement('alter table answers drop constraint answers_user_id_foreign,
add constraint answers_user_id_foreign
foreign key (user_id)
references users(id)
on delete cascade;'
);
}
function down()
{
DB::statement('alter table answers drop constraint answers_user_id_foreign,
add constraint answers_user_id_foreign
foreign key (user_id)
references users(id);'
);
}
MySQL
function up()
{
DB::statement('alter table answers drop FOREIGN KEY answers_user_id_foreign;');
DB::statement('alter table answers add constraint answers_user_id_foreign
foreign key (user_id)
references users(id)
on delete cascade;'
);
}
function down()
{
DB::statement('alter table answers drop FOREIGN KEY answers_user_id_foreign;');
DB::statement('alter table answers add constraint answers_user_id_foreign
foreign key (user_id)
references users(id);'
);
}
Solution 5 - Php
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();
});
}
Solution 6 - Php
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');
Solution 7 - Php
$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.
Solution 8 - Php
Small code
$table->foreignId('user_id')->constrained('users');