Question

在代码末尾，我想输出类的名称（E1A，R4C，...），而不是代表时间表中名称ID的数字。

有没有一种方法，而不是使用一堆if语句为变量提供不同的字符串（也许从数据库中获取）？

感谢您的帮助！

“ ...”表示之前/之后有代码。

...
<select id="class" name="class">
    <option <?php if ($class == "3" ) echo 'selected' ; ?> value="3">E1A</option>
    <option <?php if ($class == "5" ) echo 'selected' ; ?> value="5">E1B</option>
    <option <?php if ($class == "6" ) echo 'selected' ; ?> value="6">E1C</option>
    <option <?php if ($class == "15" ) echo 'selected' ; ?> value="15">G1A</option>
    <option <?php if ($class == "16" ) echo 'selected' ; ?> value="16">G1B</option>
    <option <?php if ($class == "23" ) echo 'selected' ; ?> value="23">R1A</option>
    <option <?php if ($class == "24" ) echo 'selected' ; ?> value="24">R1B</option>
    <option <?php if ($class == "25" ) echo 'selected' ; ?> value="25">R1C</option>
    <option <?php if ($class == "26" ) echo 'selected' ; ?> value="26">R1D</option>
    <option <?php if ($class == "7" ) echo 'selected' ; ?> value="7">E2A</option>
    <option <?php if ($class == "8" ) echo 'selected' ; ?> value="8">E2B</option>
    <option <?php if ($class == "9" ) echo 'selected' ; ?> value="9">E2C</option>
    <option <?php if ($class == "17" ) echo 'selected' ; ?> value="17">G2A</option>
    <option <?php if ($class == "18" ) echo 'selected' ; ?> value="18">G2B</option>
    <option <?php if ($class == "27" ) echo 'selected' ; ?> value="27">R2A</option>
    <option <?php if ($class == "28" ) echo 'selected' ; ?> value="28">R2B</option>
    <option <?php if ($class == "29" ) echo 'selected' ; ?> value="29">R2C</option>
    <option <?php if ($class == "30" ) echo 'selected' ; ?> value="30">R2D</option>
    <option <?php if ($class == "10" ) echo 'selected' ; ?> value="10">E3A</option>
    <option <?php if ($class == "11" ) echo 'selected' ; ?> value="11">E3B</option>
    <option <?php if ($class == "12" ) echo 'selected' ; ?> value="12">E3C</option>
    <option <?php if ($class == "19" ) echo 'selected' ; ?> value="19">G3A</option>
    <option <?php if ($class == "20" ) echo 'selected' ; ?> value="20">G3B</option>
    <option <?php if ($class == "31" ) echo 'selected' ; ?> value="31">R3A</option>
    <option <?php if ($class == "32" ) echo 'selected' ; ?> value="32">R3B</option>
    <option <?php if ($class == "33" ) echo 'selected' ; ?> value="33">R3C</option>
    <option <?php if ($class == "34" ) echo 'selected' ; ?> value="34">R3D</option>
    <option <?php if ($class == "13" ) echo 'selected' ; ?> value="13">E4A</option>
    <option <?php if ($class == "14" ) echo 'selected' ; ?> value="14">E4B</option>
    <option <?php if ($class == "21" ) echo 'selected' ; ?> value="21">G4A</option>
    <option <?php if ($class == "22" ) echo 'selected' ; ?> value="22">G4B</option>
    <option <?php if ($class == "35" ) echo 'selected' ; ?> value="35">R4A</option>
    <option <?php if ($class == "36" ) echo 'selected' ; ?> value="36">R4B</option>
    <option <?php if ($class == "37" ) echo 'selected' ; ?> value="37">R4C</option>
    <option <?php if ($class == "38" ) echo 'selected' ; ?> value="38">R4D</option>
    </select>
    ...
$sql = "SELECT *
FROM timetable t, class c, room r
WHERE c.id = t.class AND t.week = '".$_GET['week']."' AND t.id = '".$_GET['class']."' 
ORDER BY CASE
          WHEN Day = 'Sunday' THEN 1
          WHEN Day = 'Monday' THEN 2
          WHEN Day = 'Tuesday' THEN 3
          WHEN Day = 'Wednesday' THEN 4
          WHEN Day = 'Thursday' THEN 5
          WHEN Day = 'Friday' THEN 6
          WHEN Day = 'Saturday' THEN 7
      ELSE Day
     END ASC, Hour;
";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    echo "Timetable of the class: ".$_GET['class']."";
    ...

Answer 1

您应该能够在$ result中使用与ID相关联的名称，就像您在请求中使用“选择*”一样，但这只是一个猜测，因为我们无法知道您提供给我们的列

您是否尝试对结果进行var_dump以查看得到了什么？

Answer 2

您应该尝试此操作..单击dropdawn时，您将获得类似于3：E1A的值，将其爆炸并以所需的方式进行操作

     <select id="class" name="class">
      <option value="" selectcted>Select one</option>
    <?php
       while.....  {
       ......
       $ClassID=$SomeID;  // ID row stuff Eg 3
       $OtherValue=$SomeValue; // Eg E1A

       $VisibleValue=$OtherValue;
       $InternalValue=$ClassID . ":" . $OtherValue;

    ?>  

    <option value ="<?php echo($InternalValue) ?>"><?php echo($VisibleValue) ?> 
    </option>

    <?php } ?> // closing the While loop
    </select>

从SQL表输出行

2 个答案: