[SyS]

Basically GetPlayerIp returns 1 on success and 0 on failure.So what you doing is wrong logically.
You can do it like this way.

PHP код:

CMD:aka(playerid, params[]) 
{ 
    new query[60],pIP[16]; 
    GetPlayerIp(playerid,pIP,sizeof(pIP));
    mysql_format(mysql, query, sizeof(query),"SELECT `Username` from `players` WHERE `IP` = '%s'", pIP ); 
     
    mysql_tquery(mysql, query, "CheckAka", "i", playerid); 
    return 1; 
}