Incomplete related data with StaticConventions

[peterpp]

Version: 3.1.7

Bug Description

Code

foreach ($explorer->table('book') as $book) {
    $tags = $book->related('book_tag')->select("tag.*")->fetchPairs('name');
}

does not return tags for all books if StaticConventions is used. It looks like the problem occurs if one tag is used with multiple books. Tags are returned only for one of those books.

Interesting is that if particular column is selected from tag table, it works fine:

foreach ($explorer->table('book') as $book) {
    $tags = $book->related('book_tag')->select("tag.name")->fetchPairs('name');
}

Expected Behavior

Tags for all books should be returned.

[peterpp]

Now I understand. The problem is that book_tag doesn't have the primary key id. But StaticConventions expects that every table has a id primary key.