FIX ERROR "fc_get_datetime"

DROP TABLE IF EXISTS `tb_sys_vars`;
CREATE TABLE `tb_sys_vars` (
  `sys_vars_name` varchar(255) NOT NULL,
  `sys_vars_value` varchar(255) NOT NULL,
  `tgl_jam_buat` datetime DEFAULT NULL,
  `tgl_last_update` datetime DEFAULT NULL,
  UNIQUE KEY `sys_vars_name` (`sys_vars_name`)
);

INSERT INTO `tb_sys_vars` (`sys_vars_name`, `sys_vars_value`, `tgl_jam_buat`, `tgl_last_update`) VALUES ('kode_lokasi', '1', '2024-02-28 06:48:11', '2024-02-28 06:48:11');
INSERT INTO `tb_sys_vars` (`sys_vars_name`, `sys_vars_value`, `tgl_jam_buat`, `tgl_last_update`) VALUES ('time_zone', 'Asia/Jakarta', '2024-02-28 06:48:12', '2024-02-28 06:48:12');
INSERT INTO `tb_sys_vars` (`sys_vars_name`, `sys_vars_value`, `tgl_jam_buat`, `tgl_last_update`) VALUES ('time_zone_diff', '0', '2024-02-28 06:48:12', '2024-02-28 06:48:12');

DROP PROCEDURE IF EXISTS `st_get_datetime`;
CREATE PROCEDURE `st_get_datetime`(OUT svrDateTime datetime)
BEGIN
    DECLARE timeZone VARCHAR(255);
    DECLARE timeZoneDiff INTEGER;

    SELECT
      MAX(CASE WHEN sys_vars_name = 'time_zone' THEN sys_vars_value END) AS time_zone,
      MAX(CASE WHEN sys_vars_name = 'time_zone_diff' THEN sys_vars_value END) AS time_zone_diff
    FROM tb_sys_vars
    INTO timeZone, timeZoneDiff;

    SET time_zone = IFNULL(NULLIF(timeZone,''),'Asia/Jakarta');

    SELECT DATE_ADD(NOW(), INTERVAL IFNULL(timeZoneDiff,0) HOUR)
    INTO svrDateTime;
END;

DROP FUNCTION IF EXISTS `fc_get_datetime`;
CREATE FUNCTION `fc_get_datetime`() RETURNS datetime
BEGIN
    DECLARE tglNow DATETIME;
    CALL st_get_datetime(tglNow);
    RETURN tglNow;
END;