mysql - 在重复键更新语法上仍然重复我的数据

Question

我知道可能有人问过这个问题，但我尝试使用在这里找到的解决方案，但它们对我不起作用。如果电子邮件列存在，我需要更新数据库中的数据，如果不存在，则应该插入新记录。下面是我的代码。

       <?php

    $dbhost = 'localhost';
    $dbuser = 'root';
    $dbpass = '';
    $db = 'mbf';

    $dbconn = mysql_connect($dbhost, $dbuser, $dbpass);
    mysql_select_db($db);



    $dat = date("Y-m-d H:i:s");
    $date = new DateTime();
    $date->modify('+4 weeks');


    if(isset($_POST['submit'])) {

    $email = $_POST['email'];

          $dat = $_POST['date'];
          $ghdate = $_POST['ghdate'];
             $amount =    $_POST['amount'];
            $iniamount = $_POST['iniamount'];
           $outamount = $_POST['outamount'];
         $ghamount = $_POST['ghamount'];




         $query = "INSERT INTO donation (email, date, ghdate, amount, 
   inamount, outamount, ghamount) VALUES ('$email', '$dat', 
   '$ghdate','$amount', 
 '$iniamount', '$outamount', '$ghamount')
         ON DUPLICATE KEY UPDATE
email='$email', date='$dat', amount='$amount', inamount='$iniamount', 
outamount='$outamount', ghamount='$ghamount'";


if(mysql_query($query))
 {
 echo "<script>alert('Donation of $amount was successful');</script>";
}
 else
 {
 echo "<script>alert('FAILED TO INSERT');</script>";
 }

 }


?>

它不会更新电子邮件列，而是插入新记录。

Answer 1

ON DUPLICATE KEY UPDATE 语句仅在任何字段值违反 UNIQUE/PRIMARY KEY 约束时才有效。确保电子邮件字段在表架构中具有 UNIQUE 约束。