Question

到目前为止，这是我的PHP代码

    <?php
    $con=mysqli_connect("host","user","pass","db_name");
    // Check connection
    if (mysqli_connect_errno())
    {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    $result_set = mysqli_query($con,"SELECT points FROM total WHERE id = 1");
    $row = mysql_fetch($result_set);
    $old_total = $row['total'];
    $new_total = $old_total + $_REQUEST['total'];
    mysqli_query($con,"UPDATE total SET points = $new_total WHERE id = 1");
    mysqli_close($con);
    ?>

当我运行它时，它返回此错误： 调用未定义的函数mysql_fetch（）我错过了什么吗？

Answer 1

应该是mysqli_fetch而不是mysql_fetch。

Answer 2

你必须使用

  $row = mysqli_fetch_assoc($result_set);

而不是

  $row = mysqli_fetch($result_set);

希望它有用......

Answer 3

你应该使用$ row ['points']代替$ row ['total']和mysqli_fecth_array / assoc。

尝试以下代码：

<?php
$con=mysqli_connect("host","user","pass","db_name");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result_set = mysqli_query($con,"SELECT points FROM total WHERE id = 1");
$row = mysqli_fetch_assoc($result_set);
$old_total = $row['points'];
$new_total = $old_total + $_REQUEST['total'];
mysqli_query($con,"UPDATE total SET points = $new_total WHERE id = 1");
mysqli_close($con);
?>

Answer 4

最终守则：

$result_set = mysqli_query($con,"SELECT points FROM total WHERE id = 1");
$row = mysqli_fetch_assoc($result_set);
$old_total = $row['points'];
$new_total = $old_total + $_REQUEST['total'];
mysqli_query($con,"UPDATE total SET points = $new_total WHERE id = 1");
mysqli_close($con);
?>

mysql_fetch返回未定义的值

4 个答案: