如何阻止PHP向MYSQL数据库添加空白行/字段

Question

所以我有一个表单看起来是这样的。

<form action="thanks.php" method="post" class="niceform" name="myform">
<table>
<tr>
<td><label for="company_name">Company Name</label></td>
<td><input type="text" name="company" value="" size="38" /></td>
</tr>
// and so on

我有javascript的验证。但问题是，当我直接从localhost/mysite/form/timks.php转到thanks.php时，当我查看phpmyadmin时，会插入一个空行。Thanks.php看起来是这样的。

<?php
// open the connection
$conn = mysql_connect("localhost", "root", "password");
// pick the database to use
mysql_select_db("company_register",$conn);

$sql = "INSERT INTO `tblsignups` VALUES ('NULL', '$_POST[company]', '$_POST[email]', '$_POST[phone]', '$_POST[address]', '$_POST[comments]', '$_POST[contact_person]')";

$result = mysql_query($sql, $conn) or die(mysql_error());

mysql_close($conn);
?>
// And I have a thank you msg I display

如果有人应该直接访问thanks.php，我告诉他们先填写表单，不要在数据库中放入任何内容，我该如何检查

Answer 1

下面是一个草图示例

收到POST数据后，必须对其进行检查并发出错误标志

如果出现某些错误，请重新显示表单而不是保存表单

<?  
if ($_SERVER['REQUEST_METHOD']=='POST') {  

  $err = array();
  //performing all validations and raising corresponding errors
  if (empty($_POST['name']) $err[] = "Username field is required";  
  if (empty($_POST['text']) $err[] = "Comments field is required";  

  if (!$err) {  
    // if no errors - saving data 
    // and then redirect:
    header("Location: ".$_SERVER['PHP_SELF']);
    exit;
  }  else {
    // all field values should be escaped according to HTML standard
    foreach ($_POST as $key => $val) {
      $form[$key] = htmlspecialchars($val);
    }
} else {
  $form['name'] = $form['comments'] = '';  
}
include 'form.tpl.php';
?>  

并修改您的表单以使其能够显示错误

<? if ($err): ?>
  <? foreach($err as $e): ?>
<div class="err"><?=$e?></div>
  <? endforeach ?>
<? endif ?>
<form>
  <input type="text" name="name" value="<?=$form['name']?>">
  <textarea name="comments"><?=$form['comments']?></textarea>
  <input type="submit">
</form>

Answer 2

您需要检查表单是否已提交。你可能想要这样的东西：

<?php

if ($_POST)
{
    // open the connection
    $conn = mysql_connect("localhost", "root", "password");
    // pick the database to use
    mysql_select_db("company_register",$conn);

    $sql = "INSERT INTO `tblsignups` VALUES ('NULL', '$_POST[company]', '$_POST[email]', '$_POST[phone]', '$_POST[address]', '$_POST[comments]', '$_POST[contact_person]')";

    $result = mysql_query($sql, $conn) or die(mysql_error());

    mysql_close($conn);
}

?>

Answer 3

您可以将所有内容检查为

if(empty($_POST['company']))
{
//redirect or show error msg that its required
}
else
{
//do what you want
}

所有人都是如此。

如果你已经发布了表单，$_POST将始终为真，所以当你必须检查空值时，你必须像这样检查所有的值。

 if(empty($_POST['company']) || empty($_POST['email']) || empty($_POST['user']))

诸若此类。