SQL | Archived exercise | Compare usage proportions for 2 countries

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.

You can learn how to do this exercise on the relevant Wise Owl classroom training course (sadly for the moment only in the UK).

Software ==> SQL  (198 exercises)
Version ==> Any version of SQL Server
Topic ==> Archived  (70 exercises)
Level ==> Harder than average
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).

You need a minimum screen resolution of about 700 pixels width to see our exercises. This is because they contain diagrams and tables which would not be viewable easily on a mobile phone or small laptop. Please use a larger tablet, notebook or desktop computer, or change your screen resolution settings.

If you haven't already done so, run the stored procedure in the above folder to generate a database of the world's leading websites. The tables we will use are:

SQL exercise - Derived tables and CTEs (image 1)

The tables of interest for this exercise

Create a stored procedure which takes in as input the names of 2 countries:

SQL exercise - Derived tables and CTEs (image 2)

Here's how we might test our stored procedure

Within this stored procedure, create a CTE giving for each website the usage proportion for that website for each of the two countries specified:

SQL exercise - Derived tables and CTEs (image 3)

For Facebook, for example, 5.1% of users are French, but only 0.9% Greek

Create a SELECT statement based on this CTE to show the results with a total:

SQL exercise - Derived tables and CTEs (image 4)

We now learn that taken together French and Greek users comprise 6% of Facebook users, for example

Optionally, save your work as Country proportions.sql, then close it down.

You can unzip this file to see the answers to this exercise, although please remember this is for your personal use only.
This page has 0 threads Add post