How to specify a foreign key to multiple tables?

Question

MySQL

Hello! There are several tables: posts, comments, messages, etc. And each has an associated table post_files, comment_files, and so on. But they are essentially identical, and so I decided to combine them into one by adding a field with the type (post, message, ...,) and a common field that will connect (relationship_id). I just can't figure out how to make the foreign key work.
How can this be specified in the context of Laravel? I know how to link with one table

$table->foreign('relationship_id')->references('id')->on('posts');

But how to connect with several?
Well, or if I’m not approaching the solution of the problem correctly, then I’ll be glad if you put me on the right path :)

Answer 1

https://laravel.com/docs/5.6/eloquent-relationship...

Answer 2

how to make foreign key work

No, Mysql doesn't support it.

Answer 3

In the comments to one of the previous answers, they lied a little tangibly
->foreign () plays a role, and an essential one, because create FK at the DBMS level, which gives:
1. Integrity
2. Indexes
Another thing is that Laravel links can work without FK. That sometimes doesn't matter, and sometimes it doesn't.
And, if I remember correctly, when creating a link in Lara, indexes are not automatically created, then you will most likely need to create them explicitly.