SQL:两个日期之间的差异 [英] Sql: difference between two dates

问题描述

一个简短的问题:

我正在使用此代码

SELECT trunc (SYSDATE) - TO_DATE('04/10/2015','mm/dd/yyyy') Differenz FROM DUAL;

计算两个日期之间的差异.

to calculate the differnece between two dates.

我想补充一点，它忽略了周六，周日和节假日(不是学校假期，我的意思是圣诞节，东部假期.)我的当地时区是德国(每个国家都有自己的假期).

I would like to add that it ignores Saturdays, Sundays and holidays (not school holidays I mean holidays like christmas, eastern..). My local time zone is Germany (each country has its own holidays).

感谢帮助！

推荐答案

获取不包括周六和周日的天数并不那么困难，您可以在SO上找到一些解决方案.

Getting the number of days exclude Saturday and Sunday is not so difficult, you will find several solutions for that at SO.

考虑假期更具挑战性.一种解决方案是使用Oracle SCHEDULER.默认情况下，它用于SCHEDULER JOBS，但是我看不出有任何理由不将其用于其他目的.

Considering holidays is more challenging. One solution is be to use the Oracle SCHEDULER. By default this is used for SCHEDULER JOBS, however I don't see any reason not using it for other purpose.

最大的问题是复活节，请参阅此处:计算机. 我认为最有效的方法是对日期进行硬编码并手动进行维护.

Biggest problem is the easter day, see here: Computus. I think the most efficient way is to hard-code the dates and maintaine them manually.

BEGIN
    DBMS_SCHEDULER.CREATE_SCHEDULE('New_Year', repeat_interval => 'FREQ=YEARLY;BYDATE=0101');

    DBMS_SCHEDULER.CREATE_SCHEDULE('Easter_Sunday',  repeat_interval => 'FREQ=YEARLY;BYDATE=20150405,    20160327,    20170416,    20170416,    20180401,    20190421,    20200412', comments => 'Hard coded till 2020');
    DBMS_SCHEDULER.CREATE_SCHEDULE('Good_Friday',    repeat_interval => 'FREQ=YEARLY;BYDATE=20150405-2D, 20160327-2D, 20170416-2D, 20170416-2D, 20180401-2D, 20190421-2D, 20200412-2D');
    DBMS_SCHEDULER.CREATE_SCHEDULE('Easter_Monday',   repeat_interval => 'FREQ=YEARLY;BYDATE=20150405+1D, 20160327+1D, 20170416+1D, 20170416+1D, 20180401+1D, 20190421+1D, 20200412+1D');
    DBMS_SCHEDULER.CREATE_SCHEDULE('Ascension_Day',   repeat_interval => 'FREQ=YEARLY;BYDATE=20150405+39D,20160327+39D,20170416+39D,20170416+39D,20180401+39D,20190421+39D,20200412+39D');
    DBMS_SCHEDULER.CREATE_SCHEDULE('Pentecost_Monday', repeat_interval => 'FREQ=YEARLY;BYDATE=20150405+50D,20160327+50D,20170416+50D,20170416+50D,20180401+50D,20190421+50D,20200412+50D');

    DBMS_SCHEDULER.CREATE_SCHEDULE('Repentance_and_Prayer', repeat_interval => 'FREQ=DAILY;BYDATE=1122-SPAN:7D;BYDAY=WED', 
        comments => 'Wednesday before November 23th, Buss- und Bettag');
    -- alternative solution: 
    --DBMS_SCHEDULER.CREATE_SCHEDULE('Repentance_and_Prayer', repeat_interval => 'FREQ=MONTHLY;BYMONTH=NOV;BYDAY=3 WED', 
    --    comments => '3rd Wednesday in November');

    DBMS_SCHEDULER.CREATE_SCHEDULE('Labor_Day', repeat_interval => 'FREQ=YEARLY;BYDATE=0501');
    DBMS_SCHEDULER.CREATE_SCHEDULE('German_Unity_Day', repeat_interval => 'FREQ=YEARLY;BYDATE=1003');
    DBMS_SCHEDULER.CREATE_SCHEDULE('Christmas', repeat_interval => 'FREQ=YEARLY;BYDATE=1225+SPAN:2D');

    DBMS_SCHEDULER.CREATE_SCHEDULE('Christian_Celebration_Days', repeat_interval => 'FREQ=DAILY;INTERSECT=Easter_Sunday,Good_Friday,Easter_Monday,Ascension_Day,Pentecost_Monday,Repentance_and_Prayer,Christmas');
    -- alternative solution: 
    -- DBMS_SCHEDULER.CREATE_SCHEDULE('Christian_Celebration_Days', repeat_interval => 'FREQ=Good_Friday;BYDAY=1 MON, 6 THU,8 MON');
    DBMS_SCHEDULER.CREATE_SCHEDULE('Political_Holidays', repeat_interval => 'FREQ=DAILY;INTERSECT=New_Year,Labor_Day,German_Unity_Day');


END;
/

在此处查看日历的语法:日历语法

See syntax for calendar here: Calendaring Syntax

然后您可以使用以下时间表:

Then you can use the schedules like this:

CREATE OR REPLACE FUNCTION DateDiff(end_date IN TIMESTAMP) RETURN INTEGER AS
    next_run_date TIMESTAMP := TRUNC(SYSTIMESTAMP);
    res INTEGER := 0;
BEGIN
    IF end_date > SYSTIMESTAMP THEN
        LOOP
            DBMS_SCHEDULER.EVALUATE_CALENDAR_STRING('FREQ=DAILY;INTERVAL=1;BYDAY=MON,TUE,WED,THU,FRI; EXCLUDE=Christian_Celebration_Days,Political_Holidays', NULL, next_run_date, next_run_date);
            EXIT WHEN next_run_date >= end_date;
            res := res + 1;
        END LOOP;
        RETURN res;
    ELSE
        RAISE VALUE_ERROR;
    END IF;     
END;

SELECT DateDiff(TO_DATE('04/10/2015','mm/dd/yyyy')) AS Differenz FROM DUAL;

输出接下来的20份测试数据:

Output next 20 holiays for testing:

DECLARE
    next_run_date TIMESTAMP;
BEGIN
    FOR i IN 1..20 LOOP
        DBMS_SCHEDULER.EVALUATE_CALENDAR_STRING('FREQ=DAILY;INTERSECT='Christian_Celebration_Days,Political_Holidays', NULL, next_run_date, next_run_date);
        DBMS_OUTPUT.PUT_LINE(next_run_date);
    END LOOP;
END;

更新

我什至找到了一个更紧凑的版本:

I even found a more compact version:

BEGIN
    -- Start with first celebration day (good Friday), all dependent celebration days have to be after this day for proper calculation of schedule
    DBMS_SCHEDULER.CREATE_SCHEDULE('GOOD_FRIDAY', repeat_interval => 'FREQ=YEARLY;BYDATE=20100402,20110422,20120406,20130329,20140418,20150403,20160325,20170414,20180330,20190419,20200410,20210402,20220410,20230407,20240329,20250418,20260403,20270326,20280414,20290330,20300419', comments => 'Hard coded 2010 to 2030');
    -- Easter Sunday can be skipped for list of holidays, otherwise 'FREQ=Good_Friday;BYDAY=1 SUN+SPAN:2D'
    DBMS_SCHEDULER.CREATE_SCHEDULE('EASTER_MONDAY', repeat_interval => 'FREQ=Good_Friday;BYDAY=1 MON', comments => '1st Monday after Good Friday'
    DBMS_SCHEDULER.CREATE_SCHEDULE('ASCENSION_DAY', repeat_interval => 'FREQ=Good_Friday;BYDAY=6 THU', comments => '6th Thursday after Good Friday (40 days after Easter)');
    -- Pentecost Sunday can be skipped for list of holidays, otherwise 'FREQ=Good_Friday;BYDAY=8 SUN+SPAN:2D'
    DBMS_SCHEDULER.CREATE_SCHEDULE('PENTECOST_MONDAY', repeat_interval => 'FREQ=Good_Friday;BYDAY=8 MON', comments => '8th Monday after Good Friday (50 days after Easter)');
    DBMS_SCHEDULER.CREATE_SCHEDULE('EASTER_RELATED_DAYS', repeat_interval => 'FREQ=Good_Friday;BYDAY=1 MON, 6 THU,8 MON'
END;

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