Question

我有一个下拉列表，它是从MYSQLi查询中填充的。我希望用户选择一个选项，并从数据库中提取相关的值/记录，并根据FirstName显示给用户。

我的表没有id列（我没有做任何。以FirstName开头）

它显示带有列标题的表，但它不会从db中动态获取数据，这恰好在下面的[view code]中的while循环中编码。 我花了一整夜的时间试图解决这个问题。帮助：（

列表代码

<!DOCTYPE>
<html>
<head>
<title>Update Data</title>
</head>
<body>
<form name="form_update" method="post" action="update_test.php">
<?php
 $con=mysqli_connect("localhost","root","","ismat_db");
  //============== check connection
 if(mysqli_errno($con))
  {
echo "Can't Connect to mySQL:".mysqli_connect_error();
   }
else
{
echo "Connected to mySQL</br>";
 }

//This creates the drop down box
echo "<select name= 'FirstName'>";
echo '<option value="">'.'--- Please Select Person ---'.'</option>';
//$query=mysqli_query($con,"SELECT id,FirstName FROM persons");
$query = mysqli_query($con,"SELECT FirstName FROM persons");
//$query_display = mysqli_query($con,"SELECT * FROM persons");
while($row=mysqli_fetch_array($query))
 {
echo "<option value='". $row['id']."'>".$row['FirstName']
 .'</option>';
 }
echo '</select>';
 ?> <input type="submit" name="submit" value="Submit"/>
 </form>
 <br/><br/>
  <a href="main.html"> Go back to Main Page </a>
  </body>
  </html>

查看代码

<!DOCTYPE>
<html>
<head>
<title>Update Data</title>
</head>
<body>

<?php 
 $con=mysqli_connect("localhost","root","","ismat_db");
 if(mysqli_errno($con))
 {
echo "Can't Connect to mySQL:".mysqli_connect_error();
  }

 if(isset($_POST['FirstName']))
  {
 $name = $_POST['FirstName'];

  $fetch="SELECT Firstname FROM persons WHERE Firstname = '".$name."'";
  $result = mysqli_query($con,$fetch);
  if(!$result)
   {
   echo "Error:".(mysqli_error($con));
    }
   //display the table
  echo '<table border="1">'.'<tr>'.'<td align="center">'. 'From Database'. '</td>'.'</tr>';
  echo '<tr>'.'<td>'.'<table border="1">'.'<tr>'.'<td>'.'First Name'.'</td>'.'<td>'.'
   LastName'.'</td>'.'<td>'. 'Gender' .'</td>'.'<td>'. 'Subject'. '</td>'.'<td>'.'
   Hobbies'  .'</td>'.'</tr>';

 //Supposed to collect data from db-I tried using _array,_assoc instead of _row 
 //and got   mysqli_result()
  //   requires one parameter given boolean

 while($data=mysqli_fetch_row($result))  
     {
         echo ("<tr><td>$data[0]</td><td>$data[1]</td><td>$data[2]</td><td>$data[3]</td> <td>$data[4] </td></tr>");
}
    echo '</table>'.'</td>'.'</tr>'.'</table>';
  }
 ?>

Answer 1

您正在检查'FirstName'后期数据，这是SELECT的值。但是，此值将是其中一个OPTION的值，该值设置为ID。您应该将FirstName作为OPTION的值。

此外，您当前没有从数据库中检索ID。

Answer 2

我意识到我已经使用了PDO而不是mySqli。抛开这些琐事，如果我理解了你的问题，这应该足以让你走上正轨。

如果您运行它，您会注意到客户lastName的唯一显示时间是对表单提交的响应，其中他们是所选公司。

<强> testQuery.php

<?php
    // check if the name of the select box is present in the POST variables. if so, the form is being submitted.
    // If not, it's a fresh load of the page (the page has been requested by something other than itself)
    if (isset($_POST["selectedCustomer"]))
        $formSubmitted = true;
    else
        $formSubmitted = false;


    // connect to the mysql server
    $pdo = null;
    try
    {
        $userName = 'root';     // enter the appropriate values HERE
        $password = '';             // and HERE

        $pdo = new PDO('mysql:host=localhost', $userName, $password);
    }
    catch (PDOException $e)
    {
        die('Can\'t establish a connection to the database: ');
    }

    // create a database to answer thisa forum question
    $pdo->query("create database forumQuestion");
    $pdo->query("use forumQuestion");

    // create a table
    $queryStr = "CREATE TABLE IF NOT EXISTS `customer` (`id` int(11) NOT NULL AUTO_INCREMENT, `firstName` varchar(128) NOT NULL, `lastName` varchar(128) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ";
    $pdo->query($queryStr);

    // insert some data
    $queryStr = "INSERT INTO `customer` (`id`, `firstName`, `lastName`) VALUES (1, 'ILM 3d studios', 'Industrial Light & Magic'), (2, 'Airwalk clothing', 'Why walk on the ground?');";
    $pdo->query($queryStr);
?>

<!doctype html>
<html>
<head>
</head>
<body>
    <?php if ($formSubmitted == true)
        {
            $submittedCustomerId = $_POST["selectedCustomer"];

            $queryStr = "select * from customer where id = :id";
            $params = array(":id" => $submittedCustomerId);
            $query = $pdo->prepare($queryStr);
            $query->execute($params);

            $onlyResult = $query->fetch();
            printf("Form has been submitted.<br>");
            printf("id(%d), firstName(%s), lastName(%s)", $submittedCustomerId, $onlyResult["firstName"], $onlyResult["lastName"]);
        }
          else
            printf("Form awaiting submission");
    ?>
    <hr>
    <h2>Select a ccustomer</h2>
    <form action="testQuery.php" method="POST">
        <select name='selectedCustomer'>
            <option value='0'>-- Select a customer --</option>
            <?php
                $queryStr = "select * from customer";
                $query = $pdo->prepare($queryStr);
                $query->execute();
                while ($curCustomer = $query->fetch())
                {
                    printf("<option value='%d'>%s</option>", $curCustomer["id"], $curCustomer["firstName"]);
                }
            ?>
        </select>
        <input type='submit' value='submit form'/>
    </form>
</body>
</html>

显示数据

2 个答案: