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태그 데이터의 삭제
태그 데이터의 삭제
DELETE 구문 수행
문법
DELETE FROM TAG BEFORE TO_DATE('Time-string');
위에서 BEFORE 구문의 시간을 지정하면 그 시간 이전의 태그는 모두 삭제한다.
만일 BEFORE 구문을 지정하지 않는 경우에는 태그 테이블의 모든 데이터를 삭제한다.
일부 삭제 예제
# 현재 데이터 Mach> select * from tag; NAME TIME VALUE -------------------------------------------------------------------------------------- TAG_0001 2018-01-01 01:00:00 000:000:000 1 TAG_0001 2018-01-02 02:00:00 000:000:000 2 TAG_0001 2018-01-03 03:00:00 000:000:000 3 TAG_0001 2018-01-04 04:00:00 000:000:000 4 TAG_0001 2018-01-05 05:00:00 000:000:000 5 TAG_0001 2018-01-06 06:00:00 000:000:000 6 TAG_0001 2018-01-07 07:00:00 000:000:000 7 TAG_0001 2018-01-08 08:00:00 000:000:000 8 TAG_0001 2018-01-09 09:00:00 000:000:000 9 TAG_0001 2018-01-10 10:00:00 000:000:000 10 TAG_0002 2018-02-01 01:00:00 000:000:000 11 TAG_0002 2018-02-02 02:00:00 000:000:000 12 TAG_0002 2018-02-03 03:00:00 000:000:000 13 TAG_0002 2018-02-04 04:00:00 000:000:000 14 TAG_0002 2018-02-05 05:00:00 000:000:000 15 TAG_0002 2018-02-06 06:00:00 000:000:000 16 TAG_0002 2018-02-07 07:00:00 000:000:000 17 TAG_0002 2018-02-08 08:00:00 000:000:000 18 TAG_0002 2018-02-09 09:00:00 000:000:000 19 TAG_0002 2018-02-10 10:00:00 000:000:000 20 [20] row(s) selected. Mach> delete from tag before to_date('2018-02-01'); 10 row(s) deleted. Mach> select * from tag; NAME TIME VALUE -------------------------------------------------------------------------------------- TAG_0002 2018-02-01 01:00:00 000:000:000 11 TAG_0002 2018-02-02 02:00:00 000:000:000 12 TAG_0002 2018-02-03 03:00:00 000:000:000 13 TAG_0002 2018-02-04 04:00:00 000:000:000 14 TAG_0002 2018-02-05 05:00:00 000:000:000 15 TAG_0002 2018-02-06 06:00:00 000:000:000 16 TAG_0002 2018-02-07 07:00:00 000:000:000 17 TAG_0002 2018-02-08 08:00:00 000:000:000 18 TAG_0002 2018-02-09 09:00:00 000:000:000 19 TAG_0002 2018-02-10 10:00:00 000:000:000 20 [10] row(s) selected.
전체 삭제 예제
Mach> delete from tag; 10 row(s) deleted. Mach> select * from tag; NAME TIME VALUE -------------------------------------------------------------------------------------- [0] row(s) selected.
위와 같이 모두 삭제 되었다.
ROLLUP 데이터의 삭제
문법
DELETE FROM TAG ROLLUP BEFORE TO_DATE('Time-string');
위에서 BEFORE 구문의 시간을 지정하면 그 시간 이전의 시, 분, 초 ROLLUP 데이터가 삭제된다.
만일 BEFORE 구문을 지정하지 않는 경우에는 ROLLUP의 모든 데이터를 삭제한다.