[Sime30]

Well, I think your stock/check is wrong.

This is how my working code looks like

pawn Код:

// change name cmd
mysql_format(MySQLHandle, Query, sizeof(Query), "SELECT * FROM users WHERE PlayerName = '%s' LIMIT 1", newname);
    mysql_tquery(MySQLHandle, Query, "OnAccountChangeName", "iis", playerid,id, newname);

forward OnAccountChangeName(playerid, id, newname[]);
public OnAccountChangeName(playerid, id, newname[])
{
    if(cache_num_rows()) return SendClientMessage(playerid, COLOR_ERROR, "This name is in use!");
    // ....
    return 1;
}