months between two dates in sql server with starting and end date of each of them in sql server

Question

i want to get months between two dates with their starting and end dates.Suppose if i enter startdate as \"2017-04-01\" and enddate as \"2017-07-31\", i want list of months

Answer 1

Without recursion, using master.dbo.spt_values as a substitute for a numbers table:

declare @StartDate date = '20170401'
      , @EndDate   date = '20170731';
;with Months as (
  select top (datediff(month,@startdate,@enddate)+1) 
      [Month] = dateadd(month, row_number() over (order by number) -1, @StartDate)
    , MonthEnd = dateadd(day,-1,dateadd(month, row_number() over (order by number), @StartDate))
  from master.dbo.spt_values
  order by [Month]
)
select * from Months;

rextester demo: http://rextester.com/FXQJ4048

returns:

+------------+------------+
|   Month    |  MonthEnd  |
+------------+------------+
| 2017-04-01 | 2017-04-30 |
| 2017-05-01 | 2017-05-31 |
| 2017-06-01 | 2017-06-30 |
| 2017-07-01 | 2017-07-31 |
+------------+------------+

---

When generating a set or sequence in SQL Server, methods that avoid recursion and loops perform significantly better as the number of values increases.

Reference:

• Generate a set or sequence without loops - 1 - Aaron Bertrand
• Generate a set or sequence without loops - 2 - Aaron Bertrand
• Generate a set or sequence without loops - 3 - Aaron Bertrand

---

To get the start and end dates of each month within a given range, when the value of the @StartDate parameter is not the first day of the month:

The first option is to truncate the @StartDate parameter to the first of the month, the second option is to adjust the expressions in the common table expression to truncate the values there:

declare @StartDate date = '20170415'
      , @EndDate   date = '20170715';
/* Option 1: truncate @StartDate to the beginning of the month */
--set @StartDate = dateadd(month, datediff(month, 0, @StartDate), 0);
/* Option 2: Truncate @StartDate to month in the common table expression: */
;with Months as (
select top (datediff(month,@StartDate,@EndDate)+1) 
    [Month] = dateadd(month
               , datediff(month, 0, @StartDate) + row_number() over (order by number) -1
               , 0)
    , MonthEnd = dateadd(day,-1,dateadd(month
               , datediff(month, 0, @StartDate) + row_number() over (order by number) 
               ,0))
  from master.dbo.spt_values
  order by [Month]
)
select * from Months;