php/mysqli-mysqli_insert_id(）获取当前id并重新插入到另一个表中 - php/mysqli mysqli_insert_id() getting current id and re-inserting to another table

php/mysqli mysqli_insert_id() getting current id and re-inserting to another table

我真的不知道如何使用这个mysqli_insert_id（）函数，但下面是我要做的！

forum_threads.sql具有自动递增功能。

if(isset($_POST['createThread'])) {
    $db->real_query("INSERT INTO forum_threads (cata_id) VALUES ('1')");
    $id = mysqli_insert_id();
    $db->real_query("INSERT INTO forum_replies (thread_id) VALUES ('" .$id. ")");
}

我需要thread_id（插入forum_replys时）作为当前id（这是forum_threads内的一行，也是自动递增的）

尝试：

if(isset($_POST['createThread'])) {
    $db->real_query("INSERT INTO forum_threads (cata_id) VALUES ('1')");
    $id = $db->insert_id;
    $db->real_query("INSERT INTO forum_replies (thread_id) VALUES ('" .$id. ")");
}