如何获取两个日期之间在Informix中的工作日数 [英] How to get number of working days in Informix between two dates
问题描述
我需要在Informix中创建函数来计算两个给定日期之间的工作日数. 我用假期和两个Informix函数创建了表"prazkal":
I need to create function in Informix that calculates number of working days in between two given dates. I have created table "prazkal" with holidays, and two Informix functions:
create function is_holiday(d datetime year to day)
returning boolean;
define hcnt integer;
if weekday(d) = 0 or weekday(d) = 6 then
return 't';
end if;
---code that check if 'd' is marked as holiday in calendar
select count(*) into hcnt from prazkal where datpra = d;
if hcnt > 0 then
return 't';
end if;
return 'f';
end function;
create function work_days(start_d DATE, end_d DATE)
returning integer;
define new_d datetime year to day;
define count_days integer;
define i integer;
let i = 0;
let count_days = end_d - start_d;
let new_d = CAST(end_d AS DATETIME YEAR TO DAY);
while i < count_days
let new_d = new_d - interval(1) day to day;
if not is_holiday(new_d) then
let i = i + 1;
end if;
end while
return i;
end function;
我的两个功能都从该帖子中进行了修改. 函数work_days的结果是两个日期(end_d,start_d)之间的天数,而不是工作天数. 我在哪里出错了?
Both of my functions are modified from this post. Result of function work_days is number of days between two dates (end_d, start_d), and not number of working days. Where did I made error?
推荐答案
您的循环将i
递增,直到它是count_days
中的数字,因此答案将始终是count_days
(计算速度非常慢).您还需要第二个条件new_d > start_d
:
Your loop increments i
until it is the number in count_days
, so the answer will always be count_days
(calculated very slowly). You need a second condition new_d > start_d
too:
while i < count_days and new_d > start_d
let new_d = new_d - interval(1) day to day;
if not is_holiday(new_d) then
let i = i + 1;
end if;
end while
>
是适当的,因为循环递减然后检查new_d
,所以最后一个循环测试start_d
.
The >
is appropriate since the loop decrements and then checks new_d
, so the last cycle tests start_d
.
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