In Laravel, you can set the value of a related or relation to "null" when deleting a record from the schema itself and to do that you can make use of the "nullOnDelete()" method on the schema on Laravel 8.
<?php
$table->foreignId('forign_id')
->nullable()
->constrained("table_name")
->cascadeOnUpdate()
->nullOnDelete();Otherwise, you can also write the declaration a little bit differently which is to specify the "set null" on the "onDelete()" method for other Laravel versions.
<?php
$table
->foreignId('table_id')
->nullable()
->constrained()
->onDelete('set null');
