Question

如何检查用户和数据库之间的输入是否重复？这是用户将数据输入数据库的表单并且无论是否保存相同或不相同的记录，此代码的结果都将起作用。

    $con = mysql_connect("localhost","root","usbw");
    if (!$con)
      {
      die('Could not connect: ' . mysql_error());
      }
    mysql_select_db("booking", $con);

    $year = $_POST['year'];
    $month = $_POST['month'];
    $day = $_POST['day'];
    $time = $_POST['time'];
    $classroom = $_POST['classroom']; 
    $subject = $_POST['subject'];
    $s=implode(" ",$subject);
    $sql1 = "SELECT * FROM `test` WHERE `year` LIMIT 0, 30 ";
    $result=mysql_query("$sql1");
    $row =mysql_fetch_row($result);




        $sql = "INSERT INTO `test`(`year`, `month`, `day`, `time`, `classroom`,`subject`) VALUES  ('$year','$month','$day','$time','$classroom','$s')";



    ?>

我写了一个代码，我认为可以确定相同的记录如果相同，用户无法输入。如果不是同一个用户可以输入。代码表示如下：

if($row[1]==$year){ 
　   echo'the data was repeated';

任何人都可以帮忙解决我的if语句问题吗？

更新

if($row[1]==$year){ 
　   echo'the data was repeated';} else{
    $sql = "INSERT INTO `test`(`year`, `month`, `day`, `time`, `classroom`,`subject`) VALUES  ('$year','$month','$day','$time','$classroom','$s')";}

我写了这个语法错误....（解析错误：语法错误，意外＆＃39; @＆＃39; in）我应该使用While循环重写吗？你能告诉我如何更正代码吗？

Answer 1

$con = mysql_connect("localhost","root","usbw");
if (!$con) {
    die('Could not connect: ' . mysql_error());
}
mysql_select_db("booking", $con);

$year = $_POST['year'];
$month = $_POST['month'];
$day = $_POST['day'];
$time = $_POST['time'];
$classroom = $_POST['classroom']; 
$subject = $_POST['subject'];
$s=implode(" ",$subject);

$sql = "INSERT INTO `test`(`year`, `month`, `day`, `time`, `classroom`,`subject`) VALUES  ('$year','$month','$day','$time','$classroom','$s')";
$qr = mysql_query($sql);

if (!$qr) {
    echo mysql_error();
}

和mysql ....你需要改变典型......

CREATE TABLE `test` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `year` int(11) DEFAULT NULL,
  `month` int(11) DEFAULT NULL,
  `day` int(11) DEFAULT NULL,
  `time` int(11) DEFAULT NULL,
  `classroom` int(11) DEFAULT NULL,
  `subject` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `year` (`year`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Answer 2

您可以在mysql中的年份列上放置唯一索引。这将是所有用户的独特年份。

您可能需要2个字段（年+用户ID）的唯一索引

php if语句（如何检查用户输入的重复记录）

2 个答案: