如何获取插入行的ID和更新行？

Question

我想在我的表ID，然后更新 ID行是自动递增

if (isset($_POST['reply'])) { 
    $reply = $_POST['reply']; 
    $answers = $db->query("SELECT * FROM table_name"); 
    while($answers_ = $answers->fetch_object()){ 
     if($get_answer = $db->query("UPDATE table_name SET answer ='$reply' WHERE question_id = '$answers_->question_id' LIMIT 1")){ 
      echo "done";  
     } 
    } 
} 

我知道我的代码是错误的更新，我想只更新一行相同值的所有行

Answer 1

使用mysqli_insert_id() - 返回在最后一个查询中使用的自动生成的标识

$get_answer = $db->query("UPDATE table_name SET answer ='$reply' WHERE question_id = '$answers_->question_id' LIMIT 1") 

$last_id = mysql_insert_id();