UPDATE TB_TASK_USER_INFO
SET LOCK_AT = CASE WHEN LOCK_NCNT > 1 THEN 'Y'
ELSE ''
END
, LOCK_NCNT = IFNULL(LOCK_NCNT,0)+1
, LAST_CHG_DTM = sysdate()
WHERE TASK_USER_ID = #{id}
UPDATE TB_TASK_USER_INFO
SET LOCK_AT = NULL
, LOCK_NCNT = NULL
, LAST_CHG_DTM = sysdate()
WHERE TASK_USER_ID = #{id}