Easiest way to populate a temp table with dates between and including 2 date parameters - sql

Question

What is the easiest way to populate a temp table with dates including and between 2 date parameters. I only need the 1st day of the month dates.
So for example if #StartDate = '2011-01-01' and #EndDate = '2011-08-01'
Then I want this returned in the table
2011-01-01
2011-02-01
2011-03-01
2011-04-01
2011-05-01
2011-06-01
2011-07-01
2011-08-01

Answer 1

This works even if the #StartDate is not the first of the month. I'm assuming that if it's not the start of the month, you want to begin with the first of the next month. Otherwise remove the +1.:
;WITH cte AS (
SELECT CASE WHEN DATEPART(Day,#StartDate) = 1 THEN #StartDate
ELSE DATEADD(Month,DATEDIFF(Month,0,#StartDate)+1,0) END AS myDate
UNION ALL
SELECT DATEADD(Month,1,myDate)
FROM cte
WHERE DATEADD(Month,1,myDate) <= #EndDate
)
SELECT myDate
FROM cte
OPTION (MAXRECURSION 0)

Answer 2

declare #StartDate date = '2014-01-01';
declare #EndDate date = '2014-05-05';
;WITH cte AS (
SELECT #StartDate AS myDate
UNION ALL
SELECT DATEADD(day,1,myDate) as myDate
FROM cte
WHERE DATEADD(day,1,myDate) <= #EndDate
)
SELECT myDate
FROM cte
OPTION (MAXRECURSION 0)

Answer 3

declare #StartDate datetime
declare #EndDate datetime
select #StartDate = '2011-01-01' , #EndDate = '2011-08-01'
select #StartDate= #StartDate-(DATEPART(DD,#StartDate)-1)
declare #temp table
(
TheDate datetime
)
while (#StartDate<=#EndDate)
begin
insert into #temp
values (#StartDate )
select #StartDate=DATEADD(MM,1,#StartDate)
end
select * from #temp
Works even if the #StartDate is not the first day of the month by going back to the initial day of the month of StartDate

Answer 4

this is tested in SQL 2008 R2
Declare #StartDate datetime = '2015-03-01'
Declare #EndDate datetime = '2015-03-31'
declare #temp Table
(
DayDate datetime
);
WHILE #StartDate <= #EndDate
begin
INSERT INTO #temp (DayDate) VALUES (#StartDate);
SET #StartDate = Dateadd(Day,1, #StartDate);
end ;
select * from #temp
Result:
DayDate
-----------------------
2015-03-01 00:00:00.000
2015-03-02 00:00:00.000
2015-03-03 00:00:00.000
2015-03-04 00:00:00.000
...

Answer 5

Interestingly, it is faster to create from enumerated data as per this article.
DECLARE #StartDate DATE = '10001201';
DECLARE #EndDate DATE = '20000101';
DECLARE #dim TABLE ([date] DATE)
INSERT #dim([date])
SELECT d
FROM
(
SELECT
d = DATEADD(DAY, rn - 1, #StartDate)
FROM
(
SELECT TOP (DATEDIFF(DAY, #StartDate, #EndDate))
rn = ROW_NUMBER() OVER (ORDER BY s1.[object_id])
FROM
sys.all_objects AS s1
CROSS JOIN
sys.all_objects AS s2
ORDER BY
s1.[object_id]
) AS x
) AS y;
On my machine, it's around 60% faster with large date ranges. The recursion method can populate 2000 years worth of data in around 3 seconds though, and looks a lot nicer, so I don't really recommend this method just for incrementing days.

Answer 6

Correction for null dates:
IF OBJECT_ID('tempdb..#dim') IS NOT NULL
DROP TABLE #dim
CREATE TABLE #dim ([date] DATE)
if not #Begin_Date is null and not #End_Date is null
begin
INSERT #dim([date])
SELECT d
FROM(
SELECT
d = DATEADD(DAY, rn - 1, #Begin_Date)
FROM
(
SELECT TOP (DATEDIFF(DAY, #Begin_Date, #End_Date))
rn = ROW_NUMBER() OVER (ORDER BY s1.[object_id])
FROM
sys.all_objects AS s1
CROSS JOIN
sys.all_objects AS s2
ORDER BY
s1.[object_id]
) AS x
) AS y;
end

Answer 7

CREATE TABLE #t (d DATE)
INSERT INTO #t SELECT GETDATE()
GO
INSERT #t SELECT DATEADD(DAY, -1, MIN(d)) FROM #t
GO 10