[[HiC]TheKiller]

pawn Код:

new name[24];
mysql_escape_string(Pname(playerid), name);
format(query,sizeof(query),"SELECT * FROM `%s`  WHERE Username = %s",SQL_TABLE, name);
mysql_query(query);
mysql_store_result();
if(mysql_num_rows > 0) return SendClientMessage(playerid,COLOR_SERVER_WARNING,"[ERROR]: This username is already registered!");
mysql_free_result();

That should do it .