SQL: Cómo agrupar por año personalizado

Question

Por simplicidades, inventaré un ejemplo similar al que tengo:

Digamos que un db tiene una tabla de pedidos con un campo OrderDate y un campo Company. Luego hay una tabla de compañías y cada registro tiene un YearEndingDate (que significa que el año termina en esa fecha cada año, por ejemplo, 6/6).

Necesito sumar todos los pedidos de cada año.

Supongo que tendría que ser algo como esto, pero no puedo entenderlo:

SELECT SUM(orderValue),
CASE WHEN orderDate <= YearEndingDate THEN DatePart(year, orderDate)
CASE WHEN orderDate > YearEndingDate THEN DatePart(year, orderDate) + 1
END as Year
FROM Orders
INNER JOIN Company ON Company.companyID = Order.companyID
GROUP By Company, Year

¿Alguna idea?

Answer 1

No estoy seguro de qué RDMS está utilizando, pero esto debería ser el truco. Las partes datepart y dateadd son específicas de tsql, pero supongo que tendría acceso a funciones similares en cualquier plataforma que esté utilizando. El caso en donde determina qué valor de año utilizar.

Respuesta:

select c.companyid
      ,yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,1,o.orderdate))) as yearending
      ,sum(ordervalue) as numberoforders
  from @orders o
       join @companies c
         on o.companyid = c.companyid
 where orderdate between case when (cast(yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate)) as datetime) >= o.orderdate)
                         then yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,-1,o.orderdate)))
                         else yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate))
                          end
                     and 
                         case when (cast(yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate)) as datetime) >= o.orderdate)
                         then yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate))
                         else yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,1,o.orderdate)))
                          end
 group by c.companyid, o.orderdate, yearendingdate

Código para resolver el problema:

declare @orders table (OrderDate datetime
                      ,CompanyID varchar(20)
                      ,OrderValue int)

insert into @orders
values (getdate(),'MS',2)

insert into @orders
values (DateAdd(year, -1, getdate()),'MS',3)

insert into @orders
values (DateAdd(year, -1, getdate()),'MS',1)

insert into @orders
values (DateAdd(year, 1, getdate()),'MS',4)

insert into @orders
values (DateAdd(year, 1, getdate()),'Blizzard',2)

insert into @orders
values (getdate(),'MS',11)

declare @companies table (CompanyID varchar(20)
                         ,YearEndingDate varchar(20))

insert into @companies
values ('MS', '05/6')

insert into @companies
values ('Blizzard', '07/01')

select c.companyid
      ,o.orderdate
      ,yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate)) as sameyear
      ,yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,1,o.orderdate))) as plusyear
      ,yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,-1,o.orderdate))) as minusyear
  from @orders o
       join @companies c
         on o.companyid = c.companyid

select c.companyid
      ,yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,1,o.orderdate))) as yearending
      ,sum(ordervalue) as numberoforders
  from @orders o
       join @companies c
         on o.companyid = c.companyid
 where orderdate between case when (cast(yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate)) as datetime) >= o.orderdate)
                         then yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,-1,o.orderdate)))
                         else yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate))
                          end
                     and 
                         case when (cast(yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate)) as datetime) >= o.orderdate)
                         then yearendingdate + '/' + convert(varchar, datepart(yy, o.orderdate))
                         else yearendingdate + '/' + convert(varchar, datepart(yy, dateadd(yy,1,o.orderdate)))
                          end
 group by c.companyid, o.orderdate, yearendingdate