Oracleのn番目の稼働日を取得する

Question

Startdate、Enddate、およびWorkday（nth）を渡すと、週末と休日を除いたn番目の稼働日を計算するSQL関数が既に用意されています...

ワーキングSQL関数：私は（oracleに新）ORACLEでこの機能を再作成しようとしています

FUNCTION [dbo].[getNthWorkingDate] 
    (
@StartDate as datetime, 
@EndDate as datetime, 
@WorkDay as int 
) 
    RETURNS datetime 
    AS 
    BEGIN 
-- Declare the return variable here 
DECLARE @WorkDate as datetime, @LeaveYear as smallint,@iCount as int 
set @LeaveYear = datepart(year, @StartDate) 
set @iCount = 1 
WHILE (@StartDate < @EndDate) 
    BEGIN 

     IF (DATENAME(WEEKDAY,@StartDate) = 'SUNDAY') OR (DATENAME(WEEKDAY,@StartDate) = 'SATURDAY') 
      -- Just to keep the if statement with out code 
      set @iCount = @iCount; 
     ELSE IF EXISTS (SELECT * FROM HOLIDAYS WHERE CAST (HOLIDAY + ' ' + CAST(@LeaveYear AS VARCHAR) AS DATETIME) = @StartDate) 
      -- Just to keep the if statement with out code 
      set @iCount = @iCount; 
     ELSE 
      begin 
       set @WorkDate = @StartDate 
       if @iCount = @WorkDay 
        BREAK; 
       else 
        set @iCount = @iCount + 1; 
      end 

     set @StartDate = dateadd(day, 1, @StartDate); 
    END 
-- Return the result of the function 
RETURN @WorkDate 
END 

が、私はいくつかの変更を行いましたが、それは働いて得ることができなかった、私は中に何かが足りないと思いますルーピング、任意のヘルプは高く評価されるだろう...事前にお礼..

オラクル機能：

create or replace FUNCTION GETNTHWORKINGDATE (pStartDate DATE, 
              pEndDate DATE, 
              pWorkDay NUMBER) 
    RETURN DATE 
    AS 
    vStartDate DATE; 
    vWorkDate DATE ; 
    vCount NUMBER; 
    vHoliday DATE; 
    BEGIN 
    vCount := 1; 
    BEGIN 
    SELECT HOLIDAY_DATE INTO vHoliday FROM HOLIDAY WHERE (to_char(HOLIDAY_DATE, 'MM DD') = to_char(pStartDate, 'MM DD')); 
    EXCEPTION 
    WHEN NO_DATA_FOUND THEN  
    vHoliday := NULL; 
END;  
vStartDate := pStartDate; 

BEGIN 
WHILE (vStartDate < pEndDate) 
LOOP 
    IF (to_char(vStartDate, 'DAY') = 'SUNDAY') OR (to_char(vStartDate, 'DAY') = 'SATURDAY') THEN 
     vCount := vCount; 
    ELSIF (to_char(vHoliday, 'MM DD') = to_char(vStartDate, 'MM DD')) THEN 
     vCount := vCount; 
    ELSE  
     vWorkDate := vStartDate; 
     IF vCount = pWorkDay THEN 
     EXIT; 
     ELSE 
     vCount := vCount + 1;    
    END IF; 
    END IF; 
     vStartDate := vStartDate + 1; 
END LOOP; 

END; 

RETURN vWorkDate; 

END GETNTHWORKINGDATE; 

Answer 1

 create or replace FUNCTION GETNTHWORKINGDATE (pStartDate DATE, 
              pEndDate DATE, 
              pWorkDay NUMBER) 
RETURN DATE AS 
vStartDate DATE; 
vWorkDate DATE ; 
vCount NUMBER; 
vHoliday DATE; 

BEGIN 
vCount := 1; 
vStartDate := pStartDate; 
BEGIN 
WHILE (vStartDate < pEndDate) 
    LOOP 
     BEGIN 
      --Select Holiday Month and Date into vHoliday Variable when Start Date is a holiday. 
      SELECT HOLIDAY_DATE INTO vHoliday FROM HOLIDAY WHERE (to_char(HOLIDAY_DATE, 'MM DD') = to_char(vStartDate, 'MM DD')); 
      EXCEPTION 
      WHEN NO_DATA_FOUND THEN vHoliday := NULL; 
     END; 

    -- Code to eliminate Weekends 
    IF (to_char(vStartDate, 'D') = 1) OR (to_char(vStartDate, 'D') = 7) THEN 
     vCount := vCount; 

    --Code to eliminate Holiday's from holiday table. 
    ELSIF (to_char(vHoliday, 'MM DD') = to_char(vStartDate, 'MM DD')) THEN 
     vCount := vCount; 
    ELSE  
     vWorkDate := vStartDate; 
     IF vCount = pWorkDay THEN 
     EXIT; 
     ELSE 
     vCount := vCount + 1;    
     END IF; 
    END IF; 
    vStartDate := vStartDate + 1; 
    END LOOP;  
    END; 

RETURN vWorkDate; 

END GETNTHWORKINGDATE; 

Answer 2

このような機能は、プレーンSQLで機能します。 PL/SQLを使用する必要がない場合は、PL/SQLを使用しない方がよいでしょう。それを使用する必要がある場合は、必要に応じて適応してください。私はあなたが既に要件を変更したコメントを参照してください。必要に応じて適応してください。

「マジックナンバー」2 * :wd_number + 5は、少なくとも:wd_number平日の就業日を含む十分な暦日を追加するためのものです。 +5は:wd_numberの低い値です。これは最も効率的な解決策ではありませんが、数ミリ秒以上の時間を無駄にすることはありませんので、効率を上げるのは面倒ではありません。

with holidays(holiday_date, holiday_name) as (
     select date '2016-01-01', 'New Year''s Day' from dual union all 
     select date '2016-04-01', 'April Fools'' Day' from dual union all 
     select date '2016-05-01', 'May First'   from dual 
    ), 
    work_days (dt) as (
     select to_date(:start_date, 'yyyy-mm-dd') + level - 1 
     from dual 
     where to_char(to_date(:start_date, 'yyyy-mm-dd') + level - 1, 'Dy') 
                    not in ('Sat', 'Sun') 
     connect by level < 2 * to_number(:wd_number) + 5 
     minus 
     select holiday_date 
     from holidays 
    ), 
    ordered_work_days (dt, rn) as (
     select dt, row_number() over (order by dt) 
     from work_days 
    ) 
select dt 
from ordered_work_days 
where rn = to_number(:wd_number) 
;