Question

我是php新手。我想知道如何在我的电子邮件字段中添加重复检查。

function email_exists($email){
    global $db;
    $query = "SELECT email FROM student";
    $statement = $db->prepare($query);
    $statement->execute();
    $results = $statement->fetchAll();
    foreach ($results as $key => $result) {
        if ($result['email'] == $email){
            return true;
        }
    }
    return false;
}

我做了这个功能，但它有效但我有一个问题，当我只更新我的form.php的名称，如果电子邮件在字段中保持相同，则会出错。我想知道如何解决这个问题，如果我只更新名称而不是电子邮件。

Answer 1

尝试此查询：

$sql = "SELECT email, COUNT(*) AS count FROM student GROUP BY email HAVING count  > 0 ORDER BY count DESC;";

Answer 2

function email_exists($email){
     global $db;
     $query = "SELECT email FROM student WHERE email=:email";
     $stmt = $db->prepare($query);
     $stmt->bindParam(":email", $email);
     $stmt->execute();

  if ($stmt->rowCount() > 0) {
       return true;
      } else {
       return false;
     }
  }

Answer 3

请试试这个：

// @param email, id of updating record 
function email_exists($email, $id){
    global $db;
    $query = "SELECT email FROM student WHERE id !=".$id;
    $statement = $db->prepare($query);
    $statement->execute();
    $row_count = $statement->num_rows;// get total number of rows
    if($row_count > 0)
    {
          // record exists 
          return true;
    }
    return false;
}

使用php重复检查电子邮件字段

3 个答案: