DELIMITER //

CREATE OR REPLACE PROCEDURE cloud_addtime(
  IN date_utc DATETIME
)
/*
  Function   : 因為所有的雲端主機, 都是存 UTC, 要 -8 換為 Taipei 時間
  Description: 1.如果有多國的來源, 這個方法並不徹底, 目前先暫用
               2.目前測試 -8 看起來就正常
               3.這個 stored procedure 只是單純地在 select xx日期 時, 將時間 -8 hrs, 並不會異動資料庫的內容
                 純粹是配合 Azure Cloud 主機的運作而已
               CALL cloud_addtime(NOW());
  Build Date : 2022/12/03
  
  Modify History
    Item Who        Date       Modify Docs
    ==== ========== ========== ================================================
    1    Michael    2022/12/03 Init 
*/
BEGIN
  DECLARE date_taipei DATETIME;
  DECLARE diff_hours SMALLINT;

  SELECT pvalue INTO diff_hours FROM sys_parameter WHERE systemid = 'sys' AND pid = 'diff_hours';
  IF diff_hours IS NULL THEN
    SET diff_hours = 8;
  END IF;

  SET date_taipei = DATE_ADD(date_utc, INTERVAL diff_hours HOUR);

  SELECT date_taipei AS result; -- You can select the result or do something else with it
END //

DELIMITER ;