Adding a XOR constraint via Laravel migration

Question

I am trying to build a table of this structure using Laravel's migrations feature:

------------------------------------
| Data  | Rules | Allow | Restrict |
------------------------------------
| item1 | rule1 | 1,3   |   null   |
| item2 | rule2 | null  |  2,5,6   |
------------------------------------

As in, for each entry either Allow or Restrict must possess a not null value, but not both. I've found this comment which sounds like the condition I need, but I need to express it in a format understandable to Laravel.

Answer 1

I think there are 2 good solutions

1. Seperate the data in 2 tables

Table1 -> data, rules, constraint (FK)

Table2-> id (PK, referenced by Table1), content (allow/restrict numbers), isAllow(bool)

That way you do the constraint in the database. This is the better solution, because now you don't have null values in your database. Normalisation is a good thing.

2. Use the event listener to check before insert

https://laravel.com/docs/5.6/eloquent#events

public function creating(Table1 $t1)
{
       // check if 1 is null and 1 is not null before creating
}