为什么会出现MySQL错误“查询为空"? [英] Why do I get the MySQL Error "Query was empty"?

问题描述

$id = $_REQUEST['id'];
$Section = $_REQUEST['section'];
$Subject = $_REQUEST['subject'];
$type = $_REQUEST['type'];
$Start_date1 = isset($_REQUEST['startTxt'])?($_REQUEST['startTxt']):"";
$Venue = isset($_REQUEST['venTxt'])?($_REQUEST['venTxt']):"";
$Facilitator = isset($_REQUEST['faciTxt'])?($_REQUEST['faciTxt']):"";
$Level = isset($_REQUEST['lvlLst'])?($_REQUEST['lvlLst']):"";
$Date1 = $_REQUEST['date1'];

if(isset($_REQUEST['EDIT']))
{
    mysql_query("UPDATE service SET Start_date='$Date1', Venue='$Venue', Facilitator='$Faci' WHERE ServiceID ='$id'");
    if (!mysql_query($sql,$con))
    {
        die('Error: ' . mysql_error());
    }

    echo '<script type="text/javascript">';
    echo 'alert("Changes have been save!");';
    echo 'window.location="Admin_RecSchedMapLst.php";';
    echo '</script>';
    mysql_close($con);
}           

当我单击保存"时，它返回错误:查询为空"-这是为什么?

When I click save it returns "Error: Query was empty" - why is this?

推荐答案

您要调用mysql_query()两次，一次是使用不存在的$sql参数:

You're calling mysql_query() twice, once with a non-existent $sql parameter:

mysql_query("UPDATE service SET Start_date='$Date1', Venue='$Venue', Facilitator='$Faci' WHERE ServiceID ='$id'");
if (!mysql_query($sql,$con))

应为:

if (!mysql_query("UPDATE service SET Start_date='$Date1', Venue='$Venue', Facilitator='$Faci' WHERE ServiceID ='$id'"))

您也没有转义输入，使您可以进行SQL注入. 您应该理想地使用绑定参数，或者至少通过 mysql_real_escape_string() 运行参数.

You're also not escaping your input, leaving you open to SQL injection. You should use bound parameters ideally, or at the very least run your parameters through mysql_real_escape_string().

例如:

$Date1 = mysql_real_escape_string($Date1, $conn);

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