$mysqli = new mysqli("localhost","root","","mydatabase");

 if ($result = $mysqli->prepare("SELECT MAX(`id`) AS `id` FROM `mytable` WHERE `row1`=? OR `row2`=?"))
 {

    $id = 2;
    $result->bind_param("ii",$id,$id);
    $result->execute();
    $result->bind_result($max);
    $result->close();

    var_dump($max);

 }

 $mysqli->close();

不幸的是这段代码总是显示NULL，你能解释一下如何得到结果吗？

更新:

在控制台模式下，像这样的员工工作得很好。字段 id 是 int 和增量的(作为 PRIMARY INDEX)，其他字段只是具有不同 int 值的行，我无法更改任何内容。

更新:

好吧，看来我找到了解决方案:

 $mysqli = new mysqli("localhost","root","","mydatabase");

 if ($result = $mysqli->prepare("SELECT MAX(`id`) AS `id` FROM `mytable` WHERE `row1`=? OR `row2`=?"))
 {

    $id = 2;
    $result->bind_param("ii",$id,$id);
    $result->execute();
    $obj = $result->get_result()->fetch_object();
    $max = $obj->id;
    $result->close();

    var_dump($max);

 }

 $mysqli->close();

就是这样。

最佳答案

我是这样想的:

$result = mysqli_query($con, "SELECT * FROM `TableName` ORDER BY `PID` DESC LIMIT 1");
$row = mysqli_fetch_array($result);
$pidmax=$row['PID'];

https://stackoverflow.com/questions/10966095/