Sql-server – Dynamically Define a Range in a Dimension

pivotsql serversql-server-2008ssas

I have an issue that I face every time I decide to build a cube, and I haven't found a way to overcome it yet.

The issue is how to allow the user to define a range of things automatically without having the need to hardcode them in the dimension. I will explain my problem in an example.

I have a table called Customers:

Table Structure

this is the data in the table:

Table with data

I want to display the data in a pivot style and group up the Salary and Age in defined ranges like below:

Table with Data with Defined Range

I wrote this script and defined the ranges:

SELECT [CustId]
      ,[CustName]
      ,[Age]
      ,[Salary]
      ,[SalaryRange] = case
        when cast(salary as float) <= 500 then
            '0 - 500'
        when cast(salary as float) between 501 and 1000 then
            '501 - 1000'
        when cast(salary as float) between 1001 and 2000 then
            '1001 - 2000'
        when cast(salary as float) > 2000 then
            '2001+'
        end,
        [AgeRange] = case
        when cast(age as float) < 15 then
            'below 15'
        when cast(age as float) between 15 and 19 then
            '15 - 19'
        when cast(age as float) between 20 and 29 then
            '20 - 29'               
        when cast(age as float) between 30 and 39 then
            '30 - 39'
        when cast(age as float) >= 40 then
            '40+'
        end
  FROM [Customers]
GO

My ranges are hard coded and defined. When I copy the data to Excel and view it in a pivot table, it appears like below:

Data in Pivot Table

My problem is I want to create a cube by converting the Customers table into a fact table and create 2 dimension tables SalaryDim & AgeDim.

The SalaryDim table has 2 columns (SalaryKey,SalaryRange) and the AgeDim table is similar (ageKey,AgeRange). My Customer fact table has:

Customer
[CustId]
[CustName]
[AgeKey] --> foreign Key to AgeDim
[Salarykey] --> foreign Key to SalaryDim

I still have to define my ranges inside these dimensions. Every time I connect an Excel pivot to my cube, I can only see these hardcoded defined ranges.

My question is how to define ranges dynamically from the pivot table directly, without creating the range dimensions like AgeDim and SalaryDim. I don't want to only be stuck to the ranges defined in the dimension.

No Range Defined

The range defined is '0-25' , '26-30' , '31- 50'. I might want to change it to '0-20', '21-31' , '32-42' and so on, and users request different ranges every time.

Every time I change it, I have to change the dimension. How can I improve this process?

It would be great to have a solution implemented in the cube, so that whatever BI client tool that connects to the cube can define the ranges, but I wouldn't mind if there is a good way using Excel only.

Best Answer

HOW TO DO THIS WITH T-SQL:

As requested this is an alternative to my previous answer that showed how to do it per-user with Excel. This answer shows how to do the same thing shared/centrally using T-SQL instead. I do not know how to do Cubes, MDX or the SSAS stuff for this, so maybe Benoit or someone who does know that can post its equivalent...

1. Add SalaryRanges SQL Table and View

Create a new table called "SalaryRangeData" with the following command:

Create Table SalaryRangeData(MinVal INT Primary Key)

Add calculated columns by wrapping it in a View with this command:

CREATE VIEW SalaryRanges As
WITH
  cteSequence As
(
    Select  MinVal,
            ROW_NUMBER() OVER(Order By MinVal ASC) As Sequence
    From    SalaryRangeData
)
SELECT 
    D.Sequence,
    D.MinVal,
    COALESCE(N.MinVal - 1, 2147483645)  As MaxVal,
    CAST(D.MinVal As Varchar(32))
    + COALESCE(' - ' + CAST(N.MinVal - 1 As Varchar(32)), '+')
                        As RangeVals
FROM        cteSequence As D 
LEFT JOIN   cteSequence As N ON N.Sequence = D.Sequence + 1

Right-click on the table in SSMS and select "Edit Top 200 Rows". Then enter the following values into the MinVal cells: 0, 501, 1001, and 2001 (order doesn't matter for SQL Server, it will create it for us). Close the table-row editor and do a SELECT * FROM SalaryRanges to see all of the rows and range information.

2. Add AgeRanges SQL Table and View

Do the exact same steps as in #1 above, except replace all occurrences of "Salary" with "Age". This should make the table "AgeRangeData" and the view "AgeRanges".

Enter the following values into the AgeRangeData [MinVal] column: 0, 15, 20, 30, and 40.

3. Add Ranges to The Data

Replace your SELECT statement with CASE expressions for retrieving the data and ranges with the following one:

SELECT [CustId]
      ,[CustName]
      ,[Age]
      ,[Salary]
      ,[SalaryRange] = (
            Select RangeVals From SalaryRanges
            Where [Salary] Between MinVal And MaxVal)
      ,[AgeRange] = (
            Select RangeVals From AgeRanges
            Where [Age] Between MinVal And MaxVal)
  FROM [Customers]

4. Everything Else, The Same As Now

From here on, just do everything the same as you currently are. The ranges should all show up in your PivotTable as they currently do.

5. Test The Magic

Go to the SalaryRangeData table-row editor in SSMS again and delete the existing rows and then insert the following values: 0, 101, 201, 301, ... 2001 (again, order doesn't matter for the T-SQL solution). Go back to your PivotTable and refresh the data. And just like the Excel solution, the PivotTable ranges should be automatically changed.

Addition

HOW ADD IT TO A CUBE:

1. Create a View

CREATE VIEW CustomerView As
SELECT [CustId]
      ,[CustName]
      ,[Age]
      ,[Salary]
      ,[SalaryRange] = (
            Select RangeVals From SalaryRanges
            Where [Salary] Between MinVal And MaxVal)
      ,[AgeRange] = (
            Select RangeVals From AgeRanges
            Where [Age] Between MinVal And MaxVal)
  FROM [Customers]

1. Create a a BI Project in Visual studio and add the `CustomerView`

Connect to the Database, and add the CustomerView View in the Data Source Views to be the Fact table

Data Source Views

2. Create A cube and Define Measure & Dimension

we only need customerId, as a measure for customer count and will have the same fact table as a dimension

Measures

Dimensions

3. Add Attributes to the Dimension

Add ranges as Attributes to the Dimension

4. Connect to Cube from Excel

Add SSAS source to Excel

Select the Cube

5. View the Data of the cube in the Excel

View the Cube in Excel

6. for Any changes in the Ranges just reprocess the Dimension & cube

if you need to change the Ranges, change the data in the SalaryRangeData and AgeRangeData and then just reprocess the dimensions and the cube