在mysql中检查条目是否存在，并且不使用php插入

Question

I have got a problem with testing out if a string exists in my database!

This is what I've got so far:

$db = mysqli_connect("localhost", "database", "secret", "user");
if(!$db)
{
exit("Error: ".mysqli_connect_error());
}
$search = 'SELECT * FROM table WHERE ip = $client_ip';
$result = mysqli_query($db, $search);



while($row = mysqli_fetch_object($result)) {
        if (isset($row->blocked)) {
            echo 'You are blocked!';
        } else {
            echo 'You are not blocked!';
        }

But this won't work for me. $client_ip is defined correctly before.

Answer 1

您需要将$client_ip用引号引起来，因为它是一个字符串：

$search = "SELECT * FROM table WHERE ip = '$client_ip'";

Answer 2

试试这个：

$search = "SELECT * FROM table WHERE ip = '{$client_ip}'";