虽然循环不起作用(While loop doesn't work)

$r = mysql_query ( "SELECT guid FROM characters" );
if (mysql_num_rows($r) != 0) {
    while ( $row == mysql_fetch_array ( $r ) ) {
        $cap = rand ( 0, $char );
        if ($row ['guid'] != $cap) {
            $captain = rand ( 0, $char );
        } 
    }
} else {
    $captain = rand ( 0, $char );
}
 
 这段代码应该返回我的字符guid，它还没有记录在字符表中。 第一部分如果有效，但循环根本不起作用，我试图添加打印“文本”; 在它，但它没有返回什么。 

$r = mysql_query ( "SELECT guid FROM characters" );
if (mysql_num_rows($r) != 0) {
    while ( $row == mysql_fetch_array ( $r ) ) {
        $cap = rand ( 0, $char );
        if ($row ['guid'] != $cap) {
            $captain = rand ( 0, $char );
        } 
    }
} else {
    $captain = rand ( 0, $char );
}
 
This code should return me the guid of character, which is not recorded in the characters table yet. The first part with if works, but the loop doesn't work at all, I tried to add print "text"; in it but it didn't return nothing. 

原文：https://stackoverflow.com/questions/3326541