Mysql can two foregin keys point to the same primary key

Asked Sep 26 '16 at 18:05

Active Sep 26 '16 at 18:06

Viewed 61 times

I wonder if a mysql table can have two columns that is FK and proints to the same PK in another table like this:

Table conversations:

          $table->increments('con_id');
          $table->string('subject', 45);
          $table->integer('sender_id')->unsigned()->index();
          $table->integer('recipient_id')->unsigned()->index();
          $table->foreign('sender_id')->references('user_id')->on('users')->onDelete('cascade');
          $table->foreign('recipient_id')->references('user_id')->on('users')->onDelete('cascade');

edited Sep 26 '16 at 18:06

asked Sep 26 '16 at 18:05

user2722667

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Yes, it's perfectly fine. – Barmar Sep 26 '16 at 18:06
What problem do you have when you try it? – Barmar Sep 26 '16 at 18:06
@Barmar I dont find any problem I just wonder if it would be an issue later once the table gets bigger, peformance etc :) – user2722667 Sep 26 '16 at 18:08
No, this is perfectly normal for tables that relate two items in the same parent table, like conversations or social media friendship. – Barmar Sep 26 '16 at 18:08
@user2722667 You should have no issues – Stivan Sep 26 '16 at 18:08
@Stivan thx for looking it up (not that we didn't know ... but finding it ) – Drew Sep 26 '16 at 18:16

Mysql can two foregin keys point to the same primary key

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