PL/SQL - 基於頻率的下一個日期

Question

我在查找oracle函數或過程，根據Input Date和Frequency(Yearly,half yearly, Quarterly)計算下一個日期。

例如

Input Date  Frequency Next Occurrence Date 
1-Jan-2016  Quarterly  1-Apr-2016 
1-Jan-2016  yearly  1-Jan-2017 

Answer 1

考慮Oracle的功能ADD_MONTHS(date, number_months)獲得每月，每季度，每年的結果。

例如，下一季度將是3個月。因此，如果輸入日期是第一季度，您可以使用：

ADD_MONTHS(01-JAN-2016, 3) 

將獲得下一季度。

例如，SQL：

select TO_DATE('01-JAN-2016', 'DD-MON-YYYY') as "Input Date", 
     'Quarterly' as "Frequency", 
     ADD_MONTHS(TO_DATE('01-JAN-2016', 'DD-MON-YYYY'), 3) as "Next Occurrence Date" 
from dual 
union 
select TO_DATE('01-JAN-2016', 'DD-MON-YYYY') as "Input Date", 
     'Yearly' as "Frequency", 
     ADD_MONTHS(TO_DATE('01-JAN-2016', 'DD-MON-YYYY'), 12) as "Next Occurrence Date" 
from dual 
; 

結果：

Input Date   Frequency Next Occurrence Date 
------------------ --------- ------------------ 
01-JAN-16   Quarterly 01-APR-16 
01-JAN-16   Yearly 01-JAN-17 

Answer 2

擴展@ tale852150的回答一點，你可以使用的情況下，體現出了頻率轉換成個月增加的數量，假設你有已知的可能值列表：

add_months(input_date, case frequency 
    when 'Quarterly' then 3 
    when 'Half yearly' then 6 
    when 'Yearly' then 12 else 0 end 

快速演示：

with t (input_date, frequency) as (
    select date '2016-01-01', 'Quarterly' from dual 
    union all select date '2016-01-01', 'Half yearly' from dual 
    union all select date '2016-01-01', 'Yearly' from dual 
) 
select input_date, frequency, 
    add_months(input_date, case frequency 
    when 'Quarterly' then 3 
    when 'Half yearly' then 6 
    when 'Yearly' then 12 else 0 end) as next_occurrence_date 
from t; 

INPUT_DATE FREQUENCY NEXT_OCCURRENCE_DATE 
---------- ----------- -------------------- 
2016-01-01 Quarterly 2016-04-01   
2016-01-01 Half yearly 2016-07-01   
2016-01-01 Yearly  2017-01-01