$con=mysqli_connect($localhost,$username,$password,'db');

$query = 'SELECT  `SN` FROM `list` WHERE `Floor` LIKE "LP60" AND `type`LIKE "pc"';
$result = mysqli_query($con,$query) or die(mysqli_error());

foreach ($result as $SN)
{             
    $get = mysqli_query($con,'SELECT * FROM pc WHERE pcSN LIKE '.$SN.'ORDER BY EvenID DESC LIMIT 1')

            while ($get_row = mysqli_fetch_assoc($get)) {
                echo '<tr>'; // printing table row
                echo '<td id="ID">'.$get_row[0].'</td>';
                echo '<td>'.$get_row[1].'</td>';
                echo '<td>'.$get_row[2].'</td>';
                echo '<td>'.$get_row[3].'</td>';
                echo '<td>'.$get_row[4].'</td>';
                echo '<td>'.$get_row[5].'</td>';
                echo '<td>'.$get_row[6].'</td>';
                echo '<td>'.$get_row[7].'</td>';
                echo '<td>'.$get_row[8].'</td>';
                echo '<td>'.$get_row[9].'</td>';
                echo '<td>'.$get_row[10].'</td>';
                echo '<td>'.$get_row[11].'</td>';
                echo '<td>'.$get_row[12].'</td>';
                echo '<td>'.$get_row[13].'</td>';
                echo '<td>'.$get_row[14].'</td>';
                echo'</tr>'; // closing table row

                }
}

我已经测试了两个查询工作正常，已经测试了打印\r（$sn）以及，但在最后我得到了数组到字符串转换错误，请任何帮助
我通过使用

'" . mysqli_escape_string($con,$SN) . "'

现在像这样的新代码

$con=mysqli_connect($localhost,$username,$password,'db');

// mysql select query
$query = 'SELECT  `SN` FROM `list` WHERE `Floor` LIKE "LP60" AND `type`LIKE "pc"';
$result = mysqli_query($con,$query) or die(mysqli_error());
while($row = mysqli_fetch_assoc($result))
{
foreach ($row as $SN){

    $sql = "SELECT * FROM pc WHERE pcSN LIKE '" . mysqli_escape_string($con,$SN) . "' ORDER BY EvenID DESC LIMIT 1";
    $get = mysqli_query($con,$sql);

                while ($get_row = mysqli_fetch_assoc($get)) {
                    echo '<tr>'; // printing table row
                    echo '<td>'.$get_row['xxx'].'</td>';
                                    .
                                    .
                                    .
                                    .
                    echo '<td>'.$get_row['yyy'].'</td>';
                    echo'</tr>'; // closing table row

}
}
}

谢谢大家一直以来对我的帮助，我想把所有的点点滴滴都加起来，让一切都变好了。谢谢，希望这篇文章也能对其他人有所帮助