Question

I have the following information (return by view):

DateTime   ItemID  UserTyp Seconds

2012-01-01 10      S       12      

2012-01-01 10      S       18  

2012-01-01 11      S       22  

2012-01-02 11      M       52  

2012-01-02 10      S       120  

2012-01-02 11      S       NULL  

2012-01-03 15      M       112  

2012-01-03 12      S       182  

2012-01-04 10      M       NULL  

What I need to done is to calculated the sum of all seconds by user types, but for five periods.

The periods are set in the following way:

1. Get the first and the last date
2. Divided all days on five
3. The result of the division is the days that one period includes

Then for each period, depending on the DateTime and the UserType of the records, I should come up with this records:

Periods  UserTypeS_SUM(Seconds) UserTypeM_SUM(Seconds)
1        
2        
3
4
5

Also, I should check if there is at least 5 records, before the division is make – if I have 4 for example, only one period will be used.

I know it does not look so different, I have started to make a solution using function, but it looks kinda ineffective to me. Are there some build-in functions that could do this easy?

EDIT: I am really sorry but I have forget to mention that the I should this in view or table-valued function. No store procedures are allowed in this case.

Answer 1

try this:

;with cte as(
select *,NTILE(5) over(order by [DateTime]) as period 
from Table1
),
type_S as( select period,SUM([Seconds]) as UserTypeS_SUM
 from cte
 where [UserTyp]='S'
 group by period),
type_M as( select period,SUM([Seconds]) as UserTypeM_SUM
 from cte
 where [UserTyp]='M'
 group by period),
 seq as (
  select 1 as sno union all
  select 2 union all
  select 3 union all
  select 4 union all
  select 5  )
 select  seq.sno as period,UserTypeS_SUM, UserTypeM_SUM
 from seq 
 left join  type_s s
 on seq.sno=s.period
 left join type_m m
 on seq.sno=m.period

SQL fiddle demo