Question

我想通过此代码从插入的数据中选择随机ID到表中，当我没有从表中删除行时，此代码工作正常，我如何管理或跳过这部分代码上的已删除行：

rand($minId, $maxId)

代码：

$minId = DB::table('channel_image_container')->min('id');
$maxId = DB::table('channel_image_container')->max('id');

while (!$c = DB::table('channel_image_container')->find(rand($minId, $maxId))) {
}

echo json_encode([
    'path' => 'images/' . $c->file_name,
    'content' => $c,
    'parent' => DB::table('channel_content_type')->where('id', $c->content_id)->first()
]);

这部分代码是最好的解决方案吗？

while (!$c = DB::table('channel_image_container')->find(rand($minId, $maxId))) {
}

Answer 1

我会利用inRandomOrder() （Laravel＆gt; = 5.2）：

$c = DB::table('channel_image_container')->inRandomOrder()->first();

echo json_encode([
    'path' => 'images/' . $c->file_name,
    'content' => $c,
    'parent' => DB::table('channel_content_type')->where('id', $c->content_id)->first()
]);

Answer 2

你需要这样做：

$c = DB::table('channel_image_container')->take(1)->inRandomOrder()->get();

echo json_encode([
    'path' => 'images/' . $c->file_name,
    'content' => $c,
    'parent' => DB::table('channel_content_type')->whereId($c->content_id)->first()
]);

Laravel从表中选择随机id

2 个答案: