php - php 中的重复值 ' found in column ' id'

Question

我的数据库名称中有一个表是 mdl_assigncourses..所以我有列作为 id(主键)、groupid、courseid、status..

所以当我要将类(class)添加到组中时，如果它已经存在于表中，我想显示错误消息，如“这门类(class)已经上过”..并且它也没有存储在表中..

现在对我来说它显示了这个错误..您是否记得在调用 get_records 时将第一列设为唯一？在“id”列中发现重复值“63”。但此记录仍存储在数据库中...

这是我的插入代码:

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


$courseid = $_POST['courseid'];

$courseid = required_param('courseid', PARAM_TEXT); 
$groupid = required_param('groupid', PARAM_TEXT); 

$insert_record = new stdClass(); 
$insert_record->courseid = $courseid; 
$insert_record->groupid = $_SESSION['groupid']; 
$insert_record->assigned_date = date('Y-m-d H:i:s'); 
if($result = $DB->insert_record('assigncourses', $insert_record) ) 
{ 
   $_SESSION['successMessage'] = "record created successfully"; 
    header('Location: ' . $_SERVER['HTTP_REFERER']); 
}

//$stmt->bindParam("groupid", $_SESSION['groupid'],PDO::PARAM_STR) ;    
  } 

谁能帮帮我..怎么做..

提前致谢..

Answer 1

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

    $groupid=$_SESSION['groupid']
    $courseid = $_POST['courseid'];

    $courseid = required_param('courseid', PARAM_TEXT); 
    $groupid = required_param('groupid', PARAM_TEXT); 

    //$con is your db connection
    $sql=mysqli_query($con," SELECT * FROM mdl_assigncourses WHERE groupid='$groupid' AND courseid='$courseid' ");

    $row=mysqli_num_rows($sql);

if($row>0){

    $insert_record = new stdClass(); 
    $insert_record->courseid = $courseid; 
    $insert_record->groupid = $_SESSION['groupid']; 
    $insert_record->assigned_date = date('Y-m-d H:i:s'); 
    if($result = $DB->insert_record('assigncourses', $insert_record) ) 
    { 
       $_SESSION['successMessage'] = "record created successfully"; 
        header('Location: ' . $_SERVER['HTTP_REFERER']); 
    }

    //$stmt->bindParam("groupid", $_SESSION['groupid'],PDO::PARAM_STR) ;    
      } 

}else{
   echo "<script>alert('groupid and courseid should be unique');window.location.href='form.php';</script>";

}