Question

I have a view which pulls back 46,712 records which include the following 2 fields:

StartDate &
EndDate

I need to add a new column to be called ‘Period’, in this column I need to have each record listed as either ‘Cumulative’ or ‘Non Cumulative’

The problem with this is that firstly all of my records need to have a ‘Cumulative’ row, and every record that is active in the current month must also have a ‘Non-Cumulative’ row.

The rules that apply for a record to qualify to be classed as Non-Cumulative are the following:

EndDate = NULL

EndDate within the current month

As all my rows no matter what the criteria must have a ‘Cumulative’ row, I must therfore duplicate any rows which qualify for the ‘Non-Cumulative’ type using some sort of JOIN.

So if i have 46712 rows and 200 of these are ‘Non-Cumulative’ I should end up with 46,812 rows. (200 being duplicate apart from the Cumulative/Non Cumulative result.

Does anyone have any suggestions of how I should go about doing this.

Answer 1

If I understand the question then this should do what you need.

Declare @rowType as table (rowTypeLabel nvarchar(20))
Insert Into @rowType 
Values ('Cumulative')
Insert Into @rowType 
Values ('Non-Cumulative')

Select StartDate, EndDate, rowTypeLabel As Period
From dbo.YourTable
        Cross Join @rowType
Where (@rowType = 'Cumulative'
        Or (@rowType = 'Non-Cumulative' And ( EndDate is null
                    Or 
                 EndDate Between 
                            Cast(DateAdd(Day, 1 - Day(getDate()), getdate()) as date)
                            And
                            Cast(DateAdd(month, 1, DateAdd(Day,  - Day(getDate()), getdate())) as date))
                )