SSAS - tabular | Calculated columns exercise | Using COUNTROWS and RELATEDTABLE in calculated columns

This exercise is provided to allow potential course delegates to choose the correct Wise Owl Microsoft training course, and may not be reproduced in whole or in part in any format without the prior written consent of Wise Owl.

Software ==> SSAS - tabular  (30 exercises)
Version ==> SSAS 2012 and later
Topic ==> Calculated columns  (4 exercises)
Level ==> Average difficulty
Subject ==> SSAS training
Before you can do this exercise, you'll need to download and unzip this file (if you have any problems doing this, click here for help). Once you've done this:
  1. Go into SQL Server Management Studio;
  2. Open the SQL file you've just unzipped (you can press CTRL + O to do this); then
  3. Execute this script.

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Create a new project called Counting, importing the tables tblRegion, tblTown and tblCentre.  Create a calculated column in the region table to show how many rows there are in the centre table for each region:

Counting centres

The calculated column gives the same answer for every row.

 

The reason the answer is the same for every region is that no account is being taken of the relationship between the tables.  To solve this, use the RELATEDTABLE function to get:

Counting better

The RELATEDTABLE function returns the number of centres for each region which match up.

Create another calculated column giving the number of towns for each region:

Number of towns

The South-East has the most towns, it seems.

That's it!

You can unzip this file to see the answers to this exercise, although please remember this is for your personal use only.
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