根据php中选择的下拉项从数据库中获取文本框中的值

所以我必须根据下拉列表中选择的选项更改文本框数据。我想从数据库中提取文本框数据

例如：若我选择航空邮件，那个么航空邮件的当前弗兰克值应该显示在数据库的文本框中

这是我的密码

<div>
    <form action="alertfrank.php" method="POST" class="boxin" id="dropdown">
        <select name="type_post" required id="type_post" >
            <option value="Select Post Type" selected>Select Post Type</option>
            <option value="Airmail" >Airmail</option>
            <option value="Airmail AD">Airmail AD</option>
            <option value="Airmail Speed Post">Airmail Speed Post</option>
            <option value="Speed Post">Speed Post</option>
            <option value="Book Post">Book Post</option>
            <option value="Ordinary Post">Ordinary Post</option>
            <option value="Registered Post">Registered Post</option>
            <option value="Registered AD">Registered AD</option>
            <option value="Registered Parcel">Registered Parcel</option>
            <option value="Parcel">Parcel</option>
            <option value="Courier">Courier</option>
        </select>
        <br/>
        <br/>
        Current Frank Value <?php echo '<input type="number" name="value_frank" value="">'; ?> <br/>
        <br/>
        New Frank Value
        <input type="number" name="new_frank" placeholder="New Frank value"/>
        <br/>
        <br/>
        <input type="submit" name="submit" value="Change Value" id="sub"/>
        <br/>
        <br/>
        <br/>
        <br/>
    </form>
</div>
<?php
if (null !== (filter_input(INPUT_POST, 'submit'))) {
    mysql_connect("localhost", "root", "") or die(mysql_error());
    mysql_select_db("disp") or die(mysql_error());
    $type_post = (filter_input(INPUT_POST, 'type_post'));
    $_SESSION['type_post'] = $type_post;
    $q = mysql_query("select value_frank from frank where type_post='" . $_SESSION['type_post'] . "'") or die(mysql_error());
    $value_frank = mysql_fetch_row($q);
    $_SESSION['value_frank'] = $value_frank;
}
?>

我希望在提交前，当前弗兰克值显示在value_frank feild..中

像这样为select添加onchange

<select name="type_post" required id="type_post" onchange="get_data(this.value)" >
     <option value="Select Post Type" selected>Select Post Type</option>
     <option value="Airmail" >Airmail</option>
     <option value="Airmail AD">Airmail AD</option>
     <option value="Airmail Speed Post">Airmail Speed Post</option>
     <option value="Speed Post">Speed Post</option>
     <option value="Book Post">Book Post</option>
     <option value="Ordinary Post">Ordinary Post</option>
     <option value="Registered Post">Registered Post</option>
     <option value="Registered AD">Registered AD</option>
     <option value="Registered Parcel">Registered Parcel</option>
     <option value="Parcel">Parcel</option>
     <option value="Courier">Courier</option>
 </select>

在ajax文件中，根据选定的值从db中获取值。并显示在文本框中

您必须将数据库部分移动到此文件

mysql_connect("localhost", "root", "") or die(mysql_error());
mysql_select_db("disp") or die(mysql_error());
$type_post = (filter_input(INPUT_POST, 'type_post'));

$q = mysql_query("select value_frank from frank where type_post='" . $type_post . "'") or die(mysql_error());
$value_frank = mysql_fetch_row($q);
$val_fra = $value_frank;

echo $val_fra;// here no need to use sessions at all.

首先在文本框中添加value\u frank id，然后使用给定的jquery

$("#type_post").on('change', function(){
    $("#value_frank").val($('#type_post').val());
})

Ajax-ShowPostValue.php

创建此页面。而且，请记住，如果要更改此页面名称，也必须在标记中更改相同的名称。两者都有关联

<?
$Con=mysql_connect("localhost","root","") or die(mysql_error());
$DB=mysql_select_db($Con, "disp") or die(mysql_error());
$PostType=$_GET['PostType'];

$q= mysql_query("select value_frank from frank where type_post='$PostType'");
$RowP=mysql_fetch_array($q);

$ValueFrank=$RowP['value_frank'];
?>

<input type="number" id="HideValueFrank" name="value_frank" value="<?echo $ValueFrank;?>">

---

您希望在哪个输入文本字段中显示之前的数据值\u frank或新\u frank？@MukeshPrajapatsubmit@NanaPartykar在jquery onchange事件中使用ajax。您熟悉ajax吗？先生，请向我们展示成功函数后可以在输入文本框中获取数据的代码。在ajax成功函数中，您可以为您的字段赋值。例如：$selector.valve值

<div>
    <form action="alertfrank.php" method="POST" class="boxin" id="dropdown">
        <select name="type_post" required id="type_post" >
            <option value="Select Post Type" selected>Select Post Type</option>
            <option value="Airmail" >Airmail</option>
            <option value="Airmail AD">Airmail AD</option>
            <option value="Airmail Speed Post">Airmail Speed Post</option>
            <option value="Speed Post">Speed Post</option>
            <option value="Book Post">Book Post</option>
            <option value="Ordinary Post">Ordinary Post</option>
            <option value="Registered Post">Registered Post</option>
            <option value="Registered AD">Registered AD</option>
            <option value="Registered Parcel">Registered Parcel</option>
            <option value="Parcel">Parcel</option>
            <option value="Courier">Courier</option>
        </select>
        <br/><br/>
          Current Frank Value
         <span id='ShowValueFrank'><input type="number" id="HideValueFrank" name="value_frank" value=""></span><br/><br/>
          New Frank Value<input type="number" name="new_frank" placeholder="New Frank value"/><br/><br/>
        <input type="submit" name="submit" value="Change Value" id="sub"/><br/><br/><br/><br/>
    </form>
</div>
<script>
    $('#type_post').change(function(){
        var PostType=$('#type_post').val();
        $.ajax({url:"Ajax-ShowPostValue.php?PostType="+PostType,cache:false,success:function(result){
            $('#ShowValueFrank').html(result);
        }});
    });
</script>

<?
$Con=mysql_connect("localhost","root","") or die(mysql_error());
$DB=mysql_select_db($Con, "disp") or die(mysql_error());
$PostType=$_GET['PostType'];

$q= mysql_query("select value_frank from frank where type_post='$PostType'");
$RowP=mysql_fetch_array($q);

$ValueFrank=$RowP['value_frank'];
?>

<input type="number" id="HideValueFrank" name="value_frank" value="<?echo $ValueFrank;?>">