MySQL数据的不同表格单元格颜色

Question

所以我想改变表格单元格的背景颜色以获得不同的MySQL数据。我的情况是，当用户输入他们的体重和身高时，它会计算他们的体重指数（BMI）以及输出BMI类别。事情是这样的：

现在我该怎样更改BMI类别中，“减持”，将白色表格单元格颜色，“正常体重”为黄色，“超重”是橙色的？我试过以下，但不起作用。

这是我在我的PHP代码：

echo "<table border=\"1\"><tr><th>Name</th> //etc. 
if (mysqli_num_rows($result) == 0) 
echo "<tr><td colspan='2'>No records found.</td></tr>"; 

else { 
while ($row = mysqli_fetch_assoc($result)) 
{ 
echo "<tr><td>" . $row['Name'] . "</td>"; 
//some more codes for weight, height, BMI 
echo "<td class='<?php $tdClass; ?>'>" . $row['Health_Measure'] . "</td>"; 
} 
} 
echo "</table>"; 

if ($row['Health_Measure'] == "Underweight") 
     $tdClass = 'underweight'; 

else if ($row['Health_Measure'] == "Normal Weight") 
    $tdClass = 'normalweight'; 

else if ($row['Health_Measure'] == "Overweight") 
    $tdClass = 'overweight'; 

CSS：

.underweight { 
    background-color:white; 
} 
.normalweight { 
    background-color:yellow; 
} 
.overweight { 
    background-color:orange; 
} 

Answer 1

你只需要移动你的代码，以确定CSS类为TD在循环内，你输出表格行。

Answer 2

您的代码分配$ tdClass变量是在使用$ tdClass变量的循环之后，所以td标签将没有正确的类。将其更改为...

echo "<table border=\"1\"><tr><th>Name</th> //etc. 
if (mysqli_num_rows($result) == 0) 
echo "<tr><td colspan='2'>No records found.</td></tr>"; 

else { 
while ($row = mysqli_fetch_assoc($result)) 
{ 
    if ($row['Health_Measure'] == "Underweight") 
     $tdClass = 'underweight'; 

else if ($row['Health_Measure'] == "Normal Weight") 
    $tdClass = 'normalweight'; 

else if ($row['Health_Measure'] == "Overweight") 
    $tdClass = 'overweight'; 

echo "<tr><td>" . $row['Name'] . "</td>"; 
//some more codes for weight, height, BMI 
echo "<td class='<?php $tdClass; ?>'>" . $row['Health_Measure'] . "</td></tr>"; 
} 
} 
echo "</table>";