[ 주(Week)구하기 ] : ① ~ ⑤까지 차례대로 해본다 ① 요일번호(1:일요일~7:토요일) SELECT TO_NUMBER(TO_CHAR(TO_DATE(ATTN_DATE,'YYYYMMDD'),'D')) FROM EMPLOYEE_ATTEND WHERE ATTN_DATE LIKE '200612%' AND SNO='76990101' ② 날짜+7 SELECT TO_NUMBER(TO_CHAR(TO_DATE(ATTN_DATE,'YYYYMMDD'),'DD'))+7 FROM EMPLOYEE_ATTEND WHERE ATTN_DATE LIKE '200612%' AND SNO='76990101' ③ (날짜+7)-요일번호 SELECT TO_NUMBER(TO_CHAR(TO_DATE(ATTN_DATE,'YYYYMMDD'),'..