Question

我正在使用一个简单的验证php程序，我有2个文件，1个用于显示，1个用于控制这些是我的代码：

 <form action="comp.php" method="post">     

                <input type="text" name="reading" placeholder="kilometer reading">
                <input type="date" name="date1" placeholder="date">
                <input type="text" name="suggest" placeholder="suggested kilometer"> 
                <input type="text" name="part" placeholder="spare part">   

            <input type="submit" class="button" name="btnsubmit" value="Submit">
        </form>

这是我的控制：

$date1 = date('Y-m-d', strtotime($_POST['date1']));
$reading = $_POST['reading']; 
$suggest = $_POST['suggest'];
$part =$_POST['part'];

 $sql = "SELECT reading FROM sched ORDER BY reading DESC LIMIT 1";
 $result = mysqli_query($sqli, $sql);


      if (empty($_POST['reading']))
      {
        echo "No Input ";
        exit;
       }
        elseif ($_POST['reading'] < $result)
       {
        echo "Must input higher value than";
        exit;
       }
        elseif ($_POST['reading'] > $result)
       {
           if (($_POST['date1']) == "1970-01-01")
             {
            echo "no date input";
            exit;
           }
           else
           {
                $query = mysqli_query($sqli,"INSERT INTO sched (date,reading,suggest,part) VALUES ('$date1','$reading','$suggest','$part')");
            }
        }
}


mysqli_close($sqli);
header("Location: log.php");

我目前的最高读数为'15000'。当我的字段reading为空时，程序可以正常工作，但是如果我输入值到我的字段，它总是返回echo "Must input higher value than"; exit;，即使我输入的值高于15000.这有什么问题？

Answer 1

mysqli_query()只是向数据库提交查询以进行编译和执行。如果查询中出现错误，则返回FALSE，因此在继续之前需要测试返回的值。

如果状态不是FALSE，则$ result将是mysqli_result对象，您可以使用该对象检索查询生成的结果行。

$reading = $_POST['reading']; 
$suggest = $_POST['suggest'];
$part    = $_POST['part'];

$sql = "SELECT reading FROM sched ORDER BY reading DESC LIMIT 1";
$result = mysqli_query($sqli, $sql);
if ( $result === FALSE ) {
    echo mysql_error();
    exit;
}

$row = mysqli_fetch_object($result);
if (empty($_POST['reading'])) {
    echo "No Input ";
    exit;
}

if ($_POST['reading'] <= $row->reading) {
    echo "Must input higher value than {$row->reading}";
    exit;
}

if ($_POST['reading'] > $row->reading) {
    if (($_POST['date1']) == "1970-01-01") {
        echo "no date input";
        exit;
    } else {
        $query = mysqli_query($sqli,"INSERT INTO sched 
                                    (date,reading,suggest,part) 
                                    VALUES 
                                    ('$date1','{$row->reading}','$suggest','$part')");
    }
}

如果你不喜欢从查询返回的简单对象，你可以

$row = mysqli_fetch_assoc($result);
    if (empty($_POST['reading'])) {
        echo "No Input ";
        exit;
    }

    if ($_POST['reading'] <= $row['reading']) {
        echo "Must input higher value than {$row['reading']}";
        exit;
    }

    if ($_POST['reading'] > $row['reading']) {
        if (($_POST['date1']) == "1970-01-01") {
            echo "no date input";
            exit;
        } else {
            $query = mysqli_query($sqli,"INSERT INTO sched 
                                        (date,reading,suggest,part) 
                                        VALUES 
                                        ('$date1','{$row['reading']}','$suggest','$part')");
        }
    }

总是回到声明

1 个答案: