如何通过在下拉列表中选择 ALL 从数据库中获取所有数据

Question

我有一个包含 3 个表的数据库，表是：（产品、指令和标准）每个设备都是根据指令和标准制造的，我想创建一个带有下拉列表的网页，在那里我可以 select 一个设备来查看制定了哪些指令和标准。 我已经完成了这些，但我只能 select 一台设备。 当我按 Select all 时，如何显示所有设备的列表？

<?php
    $con = mysqli_connect("test", "test", "test", "test");
    $sql = "SELECT DISTINCT product_name from products";
    $res = mysqli_query($con, $sql);
?>




<!DOCTYP html>
<html>
    <title></title>
    <script type="text/javascript" src="fetchnDisp.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
    <style type="text/css">
        table{
            border: 1px solid;
            border-collapse: collapse;
            padding: 10px;
        }
        th, td, tr{
            border: 1px solid;
        }
        tr:nth-child(even) {
  background-color: #D6EEEE;
}

    </style>
</head>
<body>
    select Device :
    <select id="products" onchange="selectDevice()">
    <option value="">Please Choose...</option>
    <option value="all">Select All...</option>
        <?php while( $rows = mysqli_fetch_array($res)){
            ?>
            <option value="<?php echo $rows['product_name'];   ?>   " > <?php echo $rows['product_name'];  ?> </option>
        <?php    
        } 
        ?>   
    
    <select>

        <table>
        <thead>
            <th style="width: 10%"> Article Number </th>
            <th style="width: 10%"> Directive </th>
            <th style="width: 10%"> Note </th>
            <th style="width: 10%"> Standard </th>
        </thead>
        <tbody id="ans">
        </tbody>
    </table>

</body>
</html>

这是 Javascript 文件

function selectDevice(){

    var x = document.getElementById("products").value;

    $.ajax({
        url:"showDevice.php",
        method: "POST",
        data:{
            id : x
        },
        success:function(data){
            $("#ans").html(data);
        }
    })
     
}

这是 PHP 文件

<?php
    $k = $_POST['id'];
    $k = trim($k);
    $con = mysqli_connect("localhost", "test", "test", "woehler");
    $sql = "SELECT art_nr, product_name, directive, products.note, standards.standard_name FROM woehler.products left join standards on products.standard_id=standards.id WHERE product_name='{$k}'";
    $res = mysqli_query($con, $sql);
    while($rows = mysqli_fetch_array($res)){
?>
    <tr>
        <td><?php echo $rows['art_nr'];  ?> </td>
        <td><?php echo $rows['directive'];  ?> </td>
        <td><?php echo $rows['note'];  ?> </td>
        <td><?php echo $rows['standard_name'];  ?> </td>
    </tr>

<?php
    }
    echo $sql;
?>

Answer 1

在您的 PHP 文件中，如果$k k 的值等于“全部”，则WHERE product_name='{$k}'

 $sql = "SELECT art_nr, product_name, directive, products.note, standards.standard_name FROM woehler.products left join standards on products.standard_id=standards.id";

if($k != 'all'){
    $sql = "SELECT art_nr, product_name, directive, products.note, standards.standard_name FROM woehler.products left join standards on products.standard_id=standards.id WHERE product_name='{$k}'";
}

Answer 2

我使用了 if elseif，这就是它的工作原理

if ($k !="") {
    $sql = "SELECT art_nr, product_name, directive, products.note, standards.standard_name FROM woehler.products left join standards on products.standard_id=standards.id WHERE product_name='{$k}'";}
elseif ($k != "all") {
    $sql = "SELECT art_nr, product_name, directive, products.note, standards.standard_name FROM woehler.products left join standards on products.standard_id=standards.id";}

Answer 3

<?php
$k = $_POST['id'];
$k = trim($k);
$con = mysqli_connect("localhost", "test", "test", "woehler");
$sql = "SELECT art_nr, product_name, directive, products.note, standards.standard_name FROM woehler.products left join standards on products.standard_id=standards.id WHERE product_name='{$k}'";
$res = mysqli_query($con, $sql);
$html = '';
while($rows = mysqli_fetch_array($res)){
$html .= '<tr>
    <td>'.$rows['art_nr'].'</td>
    <td>'.$rows['directive'].'</td>
    <td>'.$rows['note'].'</td>
    <td>'.$rows['standard_name'].'</td>
</tr>';
}
echo $html;
?>

快乐编码！

如何通过在下拉列表中选择 ALL 从数据库中获取所有数据

问题描述

3 个解决方案

解决方案1
0 2022-07-26 06:10:19

解决方案2
0 2022-07-26 06:30:05

解决方案3
0 2022-07-26 07:08:39

如何通过在下拉列表中选择 ALL 从数据库中获取所有数据

问题描述

3 个解决方案

解决方案1 0 2022-07-26 06:10:19

解决方案2 0 2022-07-26 06:30:05

解决方案3 0 2022-07-26 07:08:39

解决方案1
0 2022-07-26 06:10:19

解决方案2
0 2022-07-26 06:30:05

解决方案3
0 2022-07-26 07:08:39