Question

我有一个注册表单的代码。我想查看电子邮件，看它是否已经登录数据库，如果是，则返回错误。

$name = $_POST['name'];
$email = $_POST['email'];

$result = mysqli_query($connection,"SELECT * FROM users WHERE email='$email'");

if($result=="")
{
echo("email was not found");
}
else
{
    echo("email was found");
}

如果结果显示为空，我遇到了麻烦。我已经尝试过使用几件事，如果找不到任何东西，就无法弄清楚如何让它正常工作。

Answer 1

使用mysqli_num_rows检查是否有任何行返回。

Answer 2

像这样使用mysqli_num_rows

if(mysqli_num_rows($result)==0) echo("email was not found"); else echo("email was found");

希望它能帮到你..

Answer 3

使用此功能。

$name = $_POST['name'];
$email = $_POST['email'];

$result = mysqli_query($connection,"SELECT * FROM users WHERE email='".$email."'");

if(!$result)
{
  echo("email was not found");
}
else
{
  echo("email was found");
}

Answer 4

if(empty($result))
{
    echo("email was not found");
}

检查mysqli_query是否没有值？

4 个答案: