通过 SQL 查询过滤并填充 <select>答案

【问题标题】：Filter through SQL query and populate <select>通过 SQL 查询过滤并填充 <select>
【发布时间】：2016-04-20 09:04:47
【问题描述】：

下面的代码运行并填充一个下拉列表。第二个、第三个和第四个查询也填充了一个下拉列表，只是在这个例子中没有。我想采用第一个下拉列表中选择的内容并过滤其他 3 个中的数据。这是PHP：

<?php
require_once('conn.php');
include '_menu.php';

//Get Processes
$smt = $stamp->prepare('SELECT tblProcess.PID, tblProcess.pName
                    FROM tblProcess
                    WHERE tblProcess.pActive=1
                    ORDER BY tblProcess.pOrder');
$smt->execute();
$data = $smt->fetchAll();

//Get Categories
$smt1 = $stamp->prepare('SELECT tblCategory.CID, tblCategory.PID, tblCategory.cName
                    FROM tblCategory
                    WHERE (((tblCategory.cActive)=1))
                    ORDER BY tblCategory.cOrder;');
$smt1->execute();
$data1 = $smt1->fetchAll();

//Get SubCategories
$smt2 = $stamp->prepare('SELECT tblCategorySub.CSID, tblCategorySub.CID, tblCategory.PID, tblCategorySub.csName
                    FROM tblCategory INNER JOIN tblCategorySub ON tblCategory.CID = tblCategorySub.CID
                    WHERE (((tblCategorySub.csActive)=1))
                    ORDER BY tblCategorySub.csOrder;');
$smt2->execute();
$data2 = $smt2->fetchAll();

//Get Cause
$smt3 = $stamp->prepare('SELECT tblCause.CauseID, tblCause.caName
                    FROM tblCause
                    WHERE (((tblCause.caActive)=1))
                    ORDER BY tblCause.caSortOrder');
$smt3->execute();
$data3 = $smt3->fetchAll();
?>

这是填充一个下拉列表的 HTML。我只包括一个来缩短这个问题。

<html>
<head>
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>

    <link type="text/css" rel="stylesheet" href="stylesheet.css"/>  
     <script src="../script/_DDDisable.js"></script>
    <title></title>
</head>
<body>
    <div id="header">
        <p id="name">STAMPING TROUBLE REPORT</p>
        <a href="mailto:you@yourdomain.com"><p id="email"></p></a>
    </div>
    <div class="right">
        <h5>Process&nbsp&nbsp&nbsp<select class="form-control" name="Process" id="Process">
            <option value="select">--Select Process--</option>
            <?php foreach ($data as $row): ?>
                <option value=$row[PID]><?=$row["pName"]?></option>
            <?php endforeach ?></select></h5>
    </div>
</body>

【问题讨论】：

标签： php jquery sql

【解决方案1】：

像这样创建您的 HTML 标记，data-belongsto 属性告诉我们我们的值应该填充到 DOM 中的哪个下拉列表。我们将在switch 语句中将ID 发送到服务器以获取用例。

<select class="form-control" name="Process" id="Process" data-belongsto="Category">


$('select.form-control').on('change', function(e){
    e.preventDefault();

    //cacheable reference to our select
    var $this = $(this);
    $.ajax({
        url: '/path/to/my/file.php',
        type: 'POST',
        data: {
            'request_type'  : $this.prop('id'),
            'request_value' : $this.val()
        },
        dataType: 'json',
        success: function(response){
            //loop over our response and append to the `belongsto` we defined earlier
            $.each(response.option, function(i,opt){
                $('#'+$this.data('belongsto').append('<option value="'+opt.PID+'"> '+opt.pName+'</option>');
            });
        }
    });
});

然后在您的文件中使用默认值执行 switch 语句。我们假设process 总是首先运行。

if(!isset($_POST['request_type']){
    //Get Processes
    $smt = $stamp->prepare('SELECT tblProcess.PID, tblProcess.pName
                    FROM tblProcess
                    WHERE tblProcess.pActive=1
                    ORDER BY tblProcess.pOrder');
    $smt->execute();
    $data = $smt->fetchAll();

} elseif(isset($_POST['request_type']) && isset($_POST['request_value'])) {
    switch($_POST['request_type']):
        case 'Categories':

           //Get Categories
           $smt1 = $stamp->prepare('SELECT tblCategory.CID, tblCategory.PID, tblCategory.cName
                    FROM tblCategory
                    WHERE (((tblCategory.cActive)=1))
                    ORDER BY tblCategory.cOrder;');
           $smt1->execute();
           $data = $smt1->fetchAll();
           break;

        case 'SubCategories':
           //Get SubCategories
           $smt2 = $stamp->prepare('SELECT tblCategorySub.CSID, tblCategorySub.CID, tblCategory.PID, tblCategorySub.csName
                    FROM tblCategory INNER JOIN tblCategorySub ON tblCategory.CID = tblCategorySub.CID
                    WHERE (((tblCategorySub.csActive)=1))
                    ORDER BY tblCategorySub.csOrder;');
           $smt2->execute();
           $data = $smt2->fetchAll();

        case 'Cause':

            //Get Cause
            $smt3 = $stamp->prepare('SELECT tblCause.CauseID, tblCause.caName
                    FROM tblCause
                    WHERE (((tblCause.caActive)=1))
                    ORDER BY tblCause.caSortOrder');
            $smt3->execute();
            $data = $smt3->fetchAll();
            break;
    endswitch;

    //exit to make sure nothing else is sent back that would alter our json response types validity
    echo json_encode($data, true); exit();
}

现在只需修改您的 SQL 语句以检查它们各自的 $_POST['request_value'] 就可以了。

【讨论】：

在你的 jQuery 中，当出于某种原因你选择一个选项而不是另一个选项时，你将总是将选项附加到下一个选择，而且附加很多比附加/连接更多的性能成本一个字符串，这让我说用 html 标记填充一个变量，而不是在循环结束时将选择内容设置为变量的内容
@Ohgodwhy，我有点困惑为什么你说我需要修改我的 SQL 语句，因为他们已经检查了它们的值。