strpos() with mysqli query - php

Question

$text = "Mike is registered on Website";
Mike is a registered user on a website and I want to find his name with strpos()
$find = $db->query("SELECT username FROM users");
$finduser = $find->fetch_object();
if(strpos($text, $finduser->username) !== false) {
echo $finduser->username." is a user on Website.";
}
But it doesn't display the echo Mike is a user on Website..
I don't know if I'm doing everything correct.
Thank you.

Answer 1

To answer your question, let me assume that you want to search all your user in database if it in the text (string) or not.
So what you want to do is loop each row of your database user and check if the username is in the text. Here's how:
while ($finduser = $find->fetch_object()) // Loop all of your database row
{
if(strpos($text, $finduser->username) !== false) {
echo $finduser->username." is a user on Website.";
}
}
What your code provide is only check for row one. Here link for the php doc http://php.net/manual/en/mysqli-result.fetch-object.php

Answer 2

Your code fetches first row from the table. If there are several rows, the first one may be not Mike. The answer of #Hernantas outputs all users just fine. But there are two other pitfalls in your question. First, your code will match user "Website" while your string is "Mike is registered on Website". It's undesirable state, right? Then, second, you should request username directly by SQL:
$searched_name = "Mike";
$find = $db->query("SELECT username FROM users
WHERE username='" . mysqli_escape_string($searched_name) . "'");
if ($finduser = $find->fetch_object()) {
echo "{$searched_name} is a user on Website.";
} else {
echo "{$searched_name} is not found.";
}