SELECT * FROM DEPARTMENT
UNION
SELECT
	'B300' AS DEPT_CODE
	,'2023-04-01' AS START_DATE
	,NULL AS END_DATE
	,'新設部門' AS DEPT_NAME
	,LAYER
	,UP_DEPT_CODE
	,VALID_FLG = '1'
	,UPDATE_USER_NAME
	,'2023-04-01 00:00:00' AS USER_UPDATE_DATETIME
FROM
	DEPARTMENT
WHERE 
    DEPT_CODE = 'A100'
;

UPDATE DEPARTMENT 
SET 
    END_DATE = '2023-03-31 23:59:59'
    ,VALID_FLG = '0'
    ,UPDATE_USER_NAME = 'ORG_CHG'
    ,USER_UPDATE_DATETIME = '2023-03-31 23:59:59'
WHERE
    DEPT_CODE = 'A100' OR DEPT_CODE = 'A200'
;

UPDATE EMP
SET
	DEPT_CODE ='B300'
	,START_DATE = '2023-04-01'
	,UPDATE_USER_NAME = 'ORG_CHG'
	,USER_UPDATE_DATETIME = '2023-04-01 00:00:00'
WHERE
	DEPT_CODE = 'A100' AND VALID_FLG = 1
	OR DEPT_CODE = 'A200' AND VALID_FLG = 1 
;

SELECT * FROM EMP;

SELECT * FROM DEPARTMENT;