Check if date is exists among the dates then add extra one day to that date - sql

Question

i want to add the days(for example 3 days) to the given date. Before adding days we can check the holidays which are already configured in one table.
Here is my sample code. But i am unable to achieve it.
declare #HolidaysList NVARCHAR(250) = '2014-06-29,2014-07-02,2014-07-18,2014-07-30,2014-10-26'
DECLARE #RDATE DATE = '2014-06-28'
declare #addDays int = 3
declare #count int = 0
while(#count < #addDays)
BEGIN
set #RDATE = DATEADD(DAY,1,#RDATE)
--print '1 ' +cast( #RDATE as nvarchar(100))
if exists(SELECT ITEM FROM fnSplit(#HolidaysList,',') WHERE item = #RDATE)
begin
SELECT #RDATE= CONVERT(VARCHAR(10),DATEADD(DAY,1,#RDATE),101)
PRINT 'if '+ CAST( #HRDATE AS NVARCHAR(100))
end
set #count = #count+1
END
PRINT #RDATE
Here fnSplit is a function which returns a table.
In the above script i have to add 3 days to #RDate. Before adding i have to check holidays list i.e in #HolidaysList. If holiday is come then we can add extra date.
in the above script the output is: 2014-08-03 because 29th is holiday and 2nd is also holiday. so output will be 2014-08-03

Answer 1

You can do this without loops:
DECLARE #Holidays TABLE (Item DATE);
INSERT #Holidays
VALUES ('2014-06-29'),('2014-07-02'),('2014-07-18'),('2014-07-30'),('2014-10-26');
DECLARE #RDATE DATE = '2014-06-28',
#addDays INT = 3;
WITH CTE AS
( SELECT *,
RowNumber = ROW_NUMBER() OVER(ORDER BY d.Date)
FROM ( SELECT DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY object_id), #RDATE)
FROM sys.all_objects
) AS d (Date)
WHERE NOT EXISTS
( SELECT 1
FROM #Holidays AS h
WHERE h.Item = d.Date
)
)
SELECT Date
FROM CTE
WHERE RowNumber = #addDays;
The principal is this part:
SELECT Date = DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY object_id), #RDATE)
FROM sys.all_objects
Will just generate a list of dates onwards from your starting date. You then exclude all holidays from this list using NOT EXISTS, and add a rank to all these days using ROW_NUMBER(). It is then just a case of selecting the date with the required rank.

Answer 2

declare #HolidaysList NVARCHAR(250) = '2014-06-29,2014-06-30,2014-07-01,2014-07-30,2014-07-18,2014-10-26'
DECLARE #RDATE DATE = '2014-06-28'
declare #addDays int = 3
declare #count int = 0
DECLARE #EXISTS int = 0
while(#count < #addDays)
BEGIN
set #RDATE = DATEADD(DAY,1,#RDATE)
if exists(SELECT ITEM FROM fnSplit(#HolidaysList,',') WHERE item = #RDATE)
set #EXISTS = #EXISTS+1
set #count = #count+1
END
if(#EXISTS is not null)
set #RDATE = DATEADD(DAY,#EXISTS,#RDATE)
print #RDATE