检查mysqli_query是否没有值？

Question

我有以下代码用于注册表单.我想检查电子邮件,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");
}

如果结果变回空洞,我会遇到麻烦.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检查是否返回了任何行.

Answer 2

mysqli_num_rows像这样使用

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