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

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 @S

Answer 1

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 2

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 3

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 4

Solution:

DECLARE  @StartDate DATETIME
        ,@EndDate DATETIME;

SELECT   @StartDate = '20110105'
        ,@EndDate = '20110815';

SELECT  DATEADD(MONTH, DATEDIFF(MONTH, 0, DATEADD(MONTH, v.number, @StartDate)), 0) AS FirstDay
--or Andriy M suggestion:
--SELECT    DATEADD(MONTH, DATEDIFF(MONTH, 0, @StartDate) + v.number, 0) AS FirstDay
INTO    #Results
FROM    master.dbo.spt_values v
WHERE   v.type = 'P'        
AND     DATEDIFF(MONTH, @StartDate, @EndDate) >= v.number;

SELECT  *
FROM    #Results;

DROP TABLE #Results;

Results:

FirstDay
-----------------------
2011-01-01 00:00:00.000
2011-02-01 00:00:00.000
2011-03-01 00:00:00.000
2011-04-01 00:00:00.000
2011-05-01 00:00:00.000
2011-06-01 00:00:00.000
2011-07-01 00:00:00.000
2011-08-01 00:00:00.000

Answer 5

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 6

CREATE TABLE #t (d DATE)

INSERT INTO #t SELECT GETDATE()

GO

INSERT #t SELECT DATEADD(DAY, -1, MIN(d)) FROM #t

GO 10