为什么数据不存储在我的数据库中?错误提示“您的SQL语法有错误” - Why won't the data be stored in my database? Error saying "You have an error in your SQL syntax;..."

Why won't the data be stored in my database? Error saying "You have an error in your SQL syntax;..."

对不起，我是php新手，所以请耐心等待。我正在创建一个用户界面，当我注册时，它说我已经注册，但它不将数据存储到数据库中。此外，每次我注册的时候，它出现错误"你有一个错误在你的SQL语法;查看与MySQL服务器版本对应的手册，了解在第1行'testing101 " '附近使用的正确语法。有人能帮帮我吗?

   <?PHP
$uname = "";
$pword = "";
$errorMessage = "";
$num_rows = 0;
function quote_smart($value, $handle) {
   if (get_magic_quotes_gpc()) {
       $value = stripslashes($value);
   }
   if (!is_numeric($value)) {
       $value = "'" . mysql_real_escape_string($value, $handle) . "'";
   }
   return $value;
}
if ($_SERVER['REQUEST_METHOD'] == 'POST'){

    $uname = $_POST['username'];
    $pword = $_POST['password'];
    $uname = htmlspecialchars($uname);
    $pword = htmlspecialchars($pword);

    $uLength = strlen($uname);
    $pLength = strlen($pword);
    if ($uLength >= 10 && $uLength <= 20) {
        $errorMessage = "";
    }
    else {
        $errorMessage = $errorMessage . "Username must be between 10 and 20 characters" . "<BR>";
    }
    if ($pLength >= 8 && $pLength <= 16) {
        $errorMessage = "";
    }
    else {
        $errorMessage = $errorMessage . "Password must be between 8 and 16 characters" . "<BR>";
    }

    if ($errorMessage == "") {
    $user_name = "root";
    $pass_word = "";
    $database = "user authentication";
    $server = "127.0.0.1";
    $db_handle = mysql_connect($server, $user_name, $pass_word);
    $db_found = mysql_select_db($database, $db_handle);
    if ($db_found) {
        $uname = quote_smart($uname, $db_handle);
        $pword = quote_smart($pword, $db_handle);


        $SQL = "SELECT * FROM login WHERE USERNAME = '".$uname."'";
        $result = mysql_query($SQL)or die(mysql_error());
        $num_rows = mysql_num_rows($result);
        if ($num_rows > 0) {
            $errorMessage = "Username already taken";
        }
        else {

    $SQL = "INSERT INTO login (USERNAME, PASSWORD) VALUES ('{$uname}', MD5('{$pword}'))"; 
            $result = mysql_query($SQL);
            mysql_close($db_handle);
        //=================================================================================
        //  START THE SESSION AND PUT SOMETHING INTO THE SESSION VARIABLE CALLED login
        //  SEND USER TO A DIFFERENT PAGE AFTER SIGN UP
        //=================================================================================
            session_start();
            $_SESSION['login'] = "1";
            header ("Location: page1.php");
        }
    }
    else {
        $errorMessage = "Database Not Found";
    }


    }
}

?>
    <html>
    <head>
    <title>Basic Login Script</title>

    </head>
    <body>

<FORM NAME ="form1" METHOD ="POST" ACTION ="signup.php">
Username: <INPUT TYPE = 'TEXT' Name ='username'  value="<?PHP print $uname;?>" maxlength="20">
Password: <INPUT TYPE = 'TEXT' Name ='password'  value="<?PHP print $pword;?>" maxlength="16">
<P>
<INPUT TYPE = "Submit" Name = "Submit1"  VALUE = "Register">

</FORM>
<P>
<?PHP print $errorMessage;?>
    </body>
    </html>

你的文本双引号:

1组引号被添加到您的smart_quote()函数中。
在实际查询中添加了一组引号，因此生成:

INSERT .... VALUES (''$uname'', ''$password'');

如果你有适当的错误处理你的查询调用，你会看到这个:

$result = mysql_query($sql) or die(mysql_error());
                           ^^^^^^^^^^^^^^^^^^^^^^