//which is better ?

    QueryResult* result = CharacterDatabase.PQuery(       
        "SELECT "
        "`character`.`data`, "          //0
        "`character`.`name`, "          //1
        "`character`.`position_x`, "    //2
        "`character`.`position_y`, "    //3
        "`character`.`position_z`, "    //4
        "`character`.`map`, "           //5
        "`character`.`totaltime`, "     //6
        "`character`.`leveltime`, "     //7
        "`character`.`at_login`,"       //7
        "`character_pet`.`entry`,"      //9
        "`character_pet`.`modelid`,"    //10
        "`character_pet`.`level` "      //11
        "FROM `character` "
        "LEFT JOIN `character_pet` "
        "ON `character`.`guid` = `character_pet`.`owner` "
        "AND `character_pet`.`slot`='0'"
        "WHERE `character`.`account` = '%u' "
        "ORDER BY `character`.`guid`", 
        m_acc_id);


//or ....

void WorldSession::HandleCharEnumOpcode( WorldPacket & /*recv_data*/ )
{
    /// get all the data necesary for loading all characters (along with their pets) on the account
    CharacterDatabase.AsyncPQuery(&chrHandler, &CharacterHandler::HandleCharEnumCallback, GetAccountId(),
    //          0                   1                   2                         3                         4                         5                   6                       7                        8
        "SELECT `character`.`data`, `character`.`name`, `character`.`position_x`, `character`.`position_y`, `character`.`position_z`, `character`.`map`, `character`.`totaltime`, `character`.`leveltime`, `character`.`at_login`,"
    //   9                       10                        11
        "`character_pet`.`entry`,`character_pet`.`modelid`,`character_pet`.`level`"
        "FROM `character` LEFT JOIN `character_pet` ON `character`.`guid`=`character_pet`.`owner` AND `character_pet`.`slot`='0'"
        "WHERE `character`.`account` = '%u' ORDER BY `character`.`guid`", GetAccountId());
}