Laravel 5.1: Factory/Seeder Pivot Tables - laravel-5.1

Question

I ma trying to create soem seeder data for a pivot table. The code below works to one point that it will hit a duplication error.
Is there a way to do this better or to improve this code so not to cause duplication.
$factory->define(Namespacehere\PostTag::class, function ($faker){
$postsId = $faker->randomElement(Namespacehere\Post::lists('id')->toArray());
$tagsId = $faker->randomElement(Namespacehere\Tag::lists('id')->toArray());
return [
'post_id' => $postsId,
'tag_id' => $tagsId
];
});
There error is
Integrity constraint violation: 1062 Duplicate entry
But on the rare occasion it passes, but i want to make sure it does all the time.
This is run with in my seeder class
public function run()
{
Namespacehere\PostTag::truncate();
factory(Namespacehere\PostTag::class, 30)->create();
}
Thanks

Answer 1

I've try to make a recursive method for checking random created ids. It's work for me;
$factory->define(App\Post::class, function ($faker) {
return [
'title' => $faker->sentence(mt_rand(3, 10)),
'content' => join("\n\n", $faker->paragraphs(mt_rand(3, 6))),
'published_at' => $faker->dateTimeBetween('-1 month', '+3 days'),
];
});
$factory->define(App\Tags::class, function ($faker) {
return [
'title' => $faker->sentence(mt_rand(1, 3)),
];
});
$PostTagFactory = function ($faker) use (&$PostTagFactory) {
$ids = [
'post_id' => $faker->randomElement(App\Post::lists('id')->toArray()),
'tag_id' => $faker->randomElement(App\Tags::lists('id')->toArray())
];
if (App\PostTag::where('post_id', $ids['post_id'])->where('tag_id', $ids['tag_id'])->first() == null) {
return $ids;
} else {
return $PostTagFactory();
}
};
$factory->define(App\PostTag::class, $PostTagFactory);