我想在动态下拉列表中显示基于 id select 的名称

Question

I want to display name in textbox based on the selected id. This id to be dynamically displayed in dropdown list, so while select it the name will displayed from the db table.

HTML code:

   <form name="insert" action="" method="post">
    <table width="100%" height="117"  border="0">
    <tr>
    <th width="27%" height="63" scope="row">ID :</th>
    <td width="73%"><select onChange="getdistrict(this.value);"  name="state" id="state" class="form-control" >
    <option value="">Select Id</option>
    <?php $query =mysqli_query($con,"SELECT * FROM patreg");
    while($row=mysqli_fetch_array($query))
    { ?>
   <option value="<?php echo $row['id'];?>"><?php echo $row['name'];?></option>
    <?php
    }
    ?>
    </select></td>
    </tr>
    <tr>
    <th scope="row">Name :</th>
    <td>
    <input type="text" id="district-list" class="form-control" value="<?php echo $row["name"]; ?>">
    </td>
    </tr>
    </table>
     </form> 

<?php
       require_once("config.php");
       if(!empty($_POST["name"])) 
       {
       $query =mysqli_query($con,"SELECT `name` FROM `patreg` WHERE `id` = '$id'");
       ?>
    <option value="">Select District</option>
    <?php
       while($row=mysqli_fetch_array($query))  
       {
       ?>
    <?php echo $row["name"]; ?>
    <?php
       }
       }
       ?>

ID = 100001 while selected name = abcdef to be displayed automatically

<script>
   function getdistrict(val) {
    $.ajax({
    type: "POST",
    url: "get_district.php",
    data:'id='+val,
    success: function(data){
        $("#district-list").html(data);
    }
    });
   }
   function selectCountry(val) {
   $("#search-box").val(val);
   $("#suggesstion-box").hide();
   }
</script>

Answer 1

Assuming that the ajax request is correctly sending the request to get_district.php with the parameter id rather than name as your code looks for then perhaps the following might help? The original code is vulnerable to SQL injection so you would be advised to use a prepared statement - the following has not been tested so excuse silly mistooks...

<?php

    # get_district.php

    require_once("config.php");

    if( $_SERVER['REQUEST_METHOD']=='POST' && !empty( $_POST['id'] ) {

        $id=$_POST['id'];

        $sql='select `name` from `patreg` where `id` =?';
        $stmt=$con->prepare( $sql );
        $stmt->bind_param( 's', $id );
        $result=$stmt->execute();

        if( $result ){

            $stmt->store_result();
            $stmt->bind_result( $name );

            echo '<option selected hidden disabled>Please select District';

            while( $stmt->fetch() ){
                printf( '<option value="%1$s">%1$s', $name );
            }

            $stmt->free_result();       
        }
        $stmt->close();
    }

?>