mssql 30 minute time intervals beteen 2 datetime

Question

I have below query and i want to get datetime in 30 min intervals between 2 datetime. Basicly I got it, but is limitited and wouln\'t return al results if the timediff is over 2

Answer 1

A tally table is a great way to deal with this type of thing. I keep one in a view to avoid using spt_values.

create View [dbo].[cteTally] as

WITH
    E1(N) AS (select 1 from (values (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))dt(n)),
    E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
    E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
    cteTally(N) AS 
    (
        SELECT  ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
    )
select N from cteTally

Then your code becomes really simple too. A small amount of datemath and voila.

declare @DateTime1 datetime = '2016/11/24 18:00:00'
    , @DateTime2 datetime = '2016/11/25 06:00:00'

select FORMAT(DATEADD(minute, (t.N - 1) * 30, @DateTime1), 'dd-HH:mm')
from cteTally t
where t.N <= (DATEDIFF(hour, @DateTime1, @DateTime2) * 2) + 1