Define foreign key constraints in Laravel migration

$table->foreignId('user_id')
  ->constrained()
  ->cascadeOnDelete();

This will do three things:

• Create an unsigned bigint column named user_id.
• Add a foreign key constraint so that user_id references the column id on a users table.
• Add the ON DELETE CASCADE referential action so that deleting the user with the id of user_id will delete the current record too.

Sources

• Foregin key constraints – Laravel docs