(233) : error 035: argument type mismatch (argument 1)
(244) : error 035: argument type mismatch (argument 1)
(245) : error 017: undefined symbol "fguery"
(245) : error 029: invalid expression, assumed zero
(245) : warning 215: expression has no effect
(468) : error 035: argument type mismatch (argument 1)
(468) : warning 213: tag mismatch
(698) : warning 203: symbol is never used: "database"

5 Errors.

new gPlayerLogged[MAX_PLAYERS];
new PlayerInfo[MAX_PLAYERS][pInfo];
new HouseInfo[MAX_HOUSES][hinfo],houseid;
new InHouse[MAX_PLAYERS],InHouseCP[MAX_PLAYERS];
new ServerSynctimer;
new mysql_connect:database, mysql_query_result:queryresult, fquery[300];

stock SetOwner(HouseName[], ownername[], houseids)
{
    format(fquery, sizeof(fquery), "INSERT INTO 'HOUSEINFO' ('housename', 'houseowner') VALUES('%s', '%s')",HouseName,ownername);
    mysql_query(database, fquery);
    format(HouseInfo[houseids][owner], 24, "%s" ,ownername);
    format(fquery,sizeof(fquery), "House Name: %s \n Owner: %s", HouseName, HouseInfo[houseids][owner]);
    UpdateDynamic3DTextLabelText(HouseInfo[houseids][textid], 0xFFFFFFFF, fquery);
    return 1;
}

stock DeleteOwner(HouseName[], houseids)
{
    format(HouseInfo[houseids][owner], 24, "%s", "\0");
    format(fquery, sizeof(fquery), "DELETE FROM 'HOUSEINFO' WHERE 'housename' = '%s'", HouseName);
    mysql_query(database, fquery);
    format(fquery, sizeof(fguery), "HouseName: %s \n House Price:$%d \n Sell Price: $%d", HouseInfo[houseids][costprice], HouseInfo[houseids][sellprice]);
    UpdateDynamic3DTextLabelText(HouseInfo[houseids][textid], 0xFFFFFFFF, fquery);
    return 1;
}

GetPlayerName(playerid, PlayerName, 24);
        format(fquery, sizeof(fquery), "SELECT `houseowner` FROM `HOUSEINFO` WHERE `houseowner` = '%s'", PlayerName); //Formats the SELECT query
        queryresult = mysql_query(database, fquery); //Query result variable is used to query
        if(mysql_num_rows(queryresult) == MAX_HOUSES_PER_PLAYER) return SendClientMessage(playerid, 0xFF000000, "REAL ESTATE agent: Your request has been declinced. Maximum private propery limit reached.");
        mysql_free_result(queryresult);