php 表单数据未插入到 mysql 数据库中，屏幕上没有出现错误？

Question

我制作了一个 php 表单并将表单条目插入到 mysql 数据库中。 php 脚本和表单依赖于同一页面。表单还使用了验证规则。最终填写所有表单条目后，当我点击提交时，我没有收到任何错误，但是当我检查我的数据库时，没有插入条目，问题是什么？如何解决？这是我的完整代码..

<?php
// define variables and set to empty values
$regErr = $nameErr = $misErr = $vbErr = $statErr = $tmErr = "";
$reg = $name = $mis = $vb = $stat = $tm = "";


if ($_SERVER["REQUEST_METHOD"] == "POST")
{
if (empty($_POST["Reg"]))
     {$regErr = "Reg ID is required";}
     else
     {
     $reg = $_POST["Reg"];
}
   if (empty($_POST["Name"]))
     {$nameErr = "Name is required";}
     else
     {
     $name = $_POST["Name"];

          // check if name only contains letters and whitespace
    if (!preg_match("/^[a-zA-Z ]*$/",$name))
     {
       $nameErr = "Only letters and white space allowed"; 
       }
   }

   if (empty($_POST["Mis"]))
     {$misErr = "Please Enter Marks";}
   else
     {
     $mis = $_POST["Mis"];
     // check if value entered is Numeric
     if(!is_numeric($mis)) {
    $misErr = "Data entered was not numeric";
     }
     }

   if (empty($_POST["Vb"]))
     {$vbErr = "Please Enter Marks";}
   else
     {
     $vb = $_POST["Vb"];
     // check if value entered is Numeric
     if(!is_numeric($vb)) {
    $vbErr = "Data entered was not numeric";
     }
     }

     if (empty($_POST["Stat"]))
     {$statErr = "Please Enter Marks";}
   else
     {
     $stat = $_POST["Stat"];
     // check if value entered is Numeric
     if(!is_numeric($stat)) {
    $statErr = "Data entered was not numeric";
     }
     }

     if (empty($_POST["Tmarks"]))
     {$tmErr = "Please Enter Marks";}
   else
     {
     $tm = $_POST["Tmarks"];
     // check if value entered is Numeric
     if(!is_numeric($tm)) {
    $tmErr = "Data entered was not numeric";
     }
     }     
}
// 1. Creating Database Connection
    $connection = mysql_connect("localhost","root");
    if ($connection) {

print "Database Found";

}
else {

print "Database NOT Found";

}
    if (!$connection){
    die("Database connection failed:".mysql_error());
    }
    // 2. Select a Database to use
    $db_select = mysql_select_db("csresult",$connection);       
    if (!$db_select) {
        die ("Database Selection failed:".mysql_error());
            }

$sql= mysql_query("INSERT INTO record ('reg', 'name', 'mis', 'vb', 'stat', 'total') VALUES ('".$reg."', '".$name."', '".$mis."', '".$vb."', '".$stat."', '".$tm."')",$connection);
echo $sql;  

echo "1 record added";  

mysql_close($connection);

?>



<form method="post" action="<?php echo $_SERVER['PHP_SELF']?>"> 
<table width=600 cellspacing=1 cellpadding=2 style='color:white;'>
<tr>
<td>Registration#:</td>
<td><input type="text" name="Reg"><span class="error">* <?php echo $regErr;?></span></td>
</tr>
<tr>
<td>Student Name:</td>
<td><input type="text" name="Name"> <span class="error">* <?php echo $nameErr;?></span></td>
</tr>
<tr>
<td>MIS Marks:</td>
<td><input type="text" name="Mis"><span class="error">*<?php echo $misErr;?></span></td>
</tr>
<tr>
<td>VB.NET Marks:</td>
<td><input type="text" name="Vb"><span class="error">*<?php echo $vbErr;?></span></td>
</tr>
<tr>
<td>Stat Marks:</td>
<td><input type="text" name="Stat"><span class="error">*<?php echo $statErr;?></span></td>
</tr>
<tr>
<td>Subject Total Marks:</td>
<td><input type="text" name="Tmarks"><span class="error">*<?php echo $tmErr;?></span></td>
</tr>
</table><br>
<p style='margin-left:300px;'><input type="submit" name="submit" value="Submit"></p>
</form>

Answer 1

您在列名周围加上了单引号。单引号用于字符串文字和日期文字。

$sql= mysql_query("INSERT INTO record ('reg', 'name', 'mis', 'vb', 'stat', 'total') ...

应该是:

$sql= mysql_query("INSERT INTO record (reg, name, mis, vb, stat, total) ...

有些人建议使用反引号，但没有必要这样做，除非您的列名包含 SQL 保留字或特殊字符。

您应该始终检查 mysql_query() 的返回值，因为如果有错误，它会返回 false。如果是这种情况，您必须自己报告错误信息。

$sql = mysql_query(...);
if ($sql === false) { die(mysql_error()); }

其他提示:

• 您正在使用已弃用的 ext/mysql 函数编写代码。您应该使用 mysqli 或 PDO。如果出现错误，这些函数也会返回 false。

• 您正在以不安全的方式编写代码。在将任何代码放到互联网上之前，请阅读有关 SQL 注入(inject)的内容:What is SQL injection?和 How can I prevent SQL injection in PHP?