# 날짜계산

/* 어제 */ 날짜칼럼 BETWEEN TRUNC(SYSDATE-1) AND TRUNC(SYSDATE-1)+0.99999421
/* 오늘 */ 날짜칼럼 BETWEEN TRUNC(SYSDATE) AND TRUNC(SYSDATE) + 0.99999421
/* 내일 */ 날짜칼럼 BETWEEN TRUNC(SYSDATE+1) AND TRUNC(SYSDATE+1)+0.99999421
/* 금주 */ 날짜칼럼 BETWEEN TRUNC(SYSDATE+1)-TO_CHAR(SYSDATE,’D’) 
                        AND TRUNC(SYSDATE+1)-TO_CHAR(SYSDATE,’D’)+6.99999421
/* 차주 */ 날짜칼럼 BETWEEN TRUNC(SYSDATE+8)-TO_CHAR(SYSDATE, ’D’) 
                        AND TRUNC(TRUNC(SYSDATE)+14.99999421)-TO_CHAR(SYSDATE, ’D’)
/* 금월 */ 날짜칼럼 BETWEEN TRUNC(SYSDATE+1)-TO_CHAR(SYSDATE,’DD’) 
                        AND TRUNC(LAST_DAY(SYSDATE))+0.99999421
/* 전월 */ 날짜칼럼 BETWEEN TRUNC(ADD_MONTHS(SYSDATE,-1)+1)-TO_CHAR(SYSDATE,’DD’) 
                        AND TRUNC(LAST_DAY(ADD_MONTHS(SYSDATE, -1)))+0.99999421
/* 차월 */ 날짜칼럼 BETWEEN ADD_MONTHS(TRUNC(SYSDATE),1)-TO_CHAR(SYSDATE,’DD’)+1 
                        AND LAST_DAY(ADD_MONTHS(TRUNC(SYSDATE),1)+0.99999421)



# 특정일 까지의 간격을 년, 개월, 일로 표현하기

SELECT 
TRUNC(MONTHS_BETWEEN(SYSDATE, TO_DATE(’19970101’, ’YYYYMMDD’))/12) "년", 
TRUNC(MONTHS_BETWEEN(SYSDATE, TO_DATE(’19970101’, ’YYYYMMDD’)) - 
TRUNC(MONTHS_BETWEEN(SYSDATE, TO_DATE(’19970101’, ’YYYYMMDD’))/12) * 12) "개월", 
TRUNC((MONTHS_BETWEEN(SYSDATE,TO_DATE(’19970101’, ’YYYYMMDD’)) - 
TRUNC(MONTHS_BETWEEN(SYSDATE, TO_DATE(’19970101’, ’YYYYMMDD’)))) * 30.5) "일" 
FROM DUAL;