条件格式化php表

Question

我需要帮助完成一项简单的任务，但我被困住了......我有一个数据库，我可以在其中提取不同的数据，并且我正在网页上可视化这些数据。 这是我获取数据的查询：

$result = mysqli_query($mysqli, "SELECT *, DATEDIFF(nextcalibration, CURDATE()) AS days FROM tools AS dp ");

这是我的桌子：

<table id="table_id" class="table table-striped">

<tr>
    <th>Nr</th> <th>Status</th> <th>name</th> <th>Serial</th> <th>Used At</th> <th>Owner</th> <th>Calibrated</th> <th>nextcalibration</th> <th>vendor</th> <th>days</th> <th>actions</th>
</tr>
<?php

while($user_data = mysqli_fetch_array($result)) 
{
    echo "<tr>";
    echo "<td>".$user_data['toolnr']."</td>";
    echo "<td>".$user_data['status']."</td>";
    echo "<td>".$user_data['toolname']."</td>";
    echo "<td>".$user_data['serial']."</td>";
    echo "<td>".$user_data['usedat']."</td>";
    echo "<td>".$user_data['owner']."</td>";
    echo "<td>".$user_data['calibrated']."</td>";
    echo "<td>".$user_data['nextcalibration']."</td>";
    echo "<td>".$user_data['vendors']."</td>";
    echo "<td>".$user_data['days']. "</td>";
    echo "<td><a href='edit.php?id=$user_data[id]'><img src='img/edit.png' ></a> | <a href='delete.php?id=$user_data[id]' onclick='return checkDelete()'><img src='img/delete.png'></a></td></tr>";
}

?>
</table>

我只想为最后一列 - "days"进行条件格式设置。 这个想法是如果"days" <= 30变成红色文本。 我尝试了各种 JS，但老实说，它不起作用。

Answer 1

像这样简单的东西 - 没有 JS - 会起作用吗？

<table id="table_id" class="table table-striped">

<tr>
    <th>Nr</th> <th>Status</th> <th>name</th> <th>Serial</th> <th>Used At</th> <th>Owner</th> <th>Calibrated</th> <th>nextcalibration</th> <th>vendor</th> <th>days</th> <th>actions</th>
</tr>
<?php

while($user_data = mysqli_fetch_array($result)) 
{
    $style_days=($user_data['days']<=30)?'style="color:red"':'';
    echo "<tr>";
    echo "<td>".$user_data['toolnr']."</td>";
    echo "<td>".$user_data['status']."</td>";
    echo "<td>".$user_data['toolname']."</td>";
    echo "<td>".$user_data['serial']."</td>";
    echo "<td>".$user_data['usedat']."</td>";
    echo "<td>".$user_data['owner']."</td>";
    echo "<td>".$user_data['calibrated']."</td>";
    echo "<td>".$user_data['nextcalibration']."</td>";
    echo "<td>".$user_data['vendors']."</td>";
    echo "<td ".$style_days.">".$user_data['days']. "</td>";
    echo "<td><a href='edit.php?id=$user_data[id]'><img src='img/edit.png' ></a> | <a href='delete.php?id=$user_data[id]' onclick='return checkDelete()'><img src='img/delete.png'></a></td></tr>";
}

?>
</table>

当然，对$user_data['days'] (existence, numeric..) 应用必要的保护:)

Answer 2

<table id="table_id" class="table table-striped">

<tr>
    <th>Nr</th> <th>Status</th> <th>name</th> <th>Serial</th> <th>Used At</th> <th>Owner</th> <th>Calibrated</th> <th>nextcalibration</th> <th>vendor</th> <th>days</th> <th>actions</th>
</tr>
<?php

while($user_data = mysqli_fetch_array($result)) 
{
    echo "<tr>";
    echo "<td>".$user_data['toolnr']."</td>";
    echo "<td>".$user_data['status']."</td>";
    echo "<td>".$user_data['toolname']."</td>";
    echo "<td>".$user_data['serial']."</td>";
    echo "<td>".$user_data['usedat']."</td>";
    echo "<td>".$user_data['owner']."</td>";
    echo "<td>".$user_data['calibrated']."</td>";
    echo "<td>".$user_data['nextcalibration']."</td>";
    echo "<td>".$user_data['vendors']."</td>";
    echo "<td>";
    $days=$user_data['days'];
    if($days <= 30){
        echo "<span style='color:red;'>$days</span>";
    }else{
        echo $days;
    }
    echo "</td>";
    echo "<td><a href='edit.php?id=$user_data[id]'><img src='img/edit.png' ></a> | <a href='delete.php?id=$user_data[id]' onclick='return checkDelete()'><img src='img/delete.png'></a></td></tr>";
}

?>
</table>