Power Query: Revision Time – Part 7
22 May 2024
Welcome to our Power Query blog. Today, I continue to create a refreshable revision timetable by randomising the subject slots I need for the timetable.
As my salespeople take a well-earned break, many students here in the UK are preparing for exams in the summer. To help my own offspring get organised, I volunteered to create a refreshable printable revision timetable. This is the result:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image1-1715274309.png/9fa4928e14c7422c8be9c83417b61922.jpg)
I needed a list of topics, and to begin with, I created extra entries for topics that required more timeslots:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image2-1715274356.png/2734faf8bb0c4e8f3c8cb772fe0d7ba3.jpg)
We agreed on half-hourly slots, and I created a grid so that my daughter could indicate the slots that she wouldn’t be able to revise.
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image3-1715274377.png/bbef9530a5dd6e6f91072736ed0f9cc7.jpg)
When I first designed the solution, I included some Excel functions, but since this is a Power Query blog, I will ensure that I only use Power Query functions (apart from some formatting at the end!).
In Part 1, I converted my data into two [2] Tables: Subjects and Availability. I extracted Subjects to Power Query.
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image4-1715274404.png/413d7ef9314ea3ca270945c0b5f5b027.jpg)
I created the Availability query by taking a copy of Subjects, and amending it:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image5-1715274421.png/c10f40de073ab43a9f508ece457af593.jpg)
In Part 2, and Part 3, I calculated the number of subjects and the number of slots on Availability.
This gave me both totals:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image6-1715274443.png/2cfbc9eb1a21686e35d2beb4789969e5.jpg)
In Part 4, I calculated how many times each subject will appear in a new query, remembering to round up to whole slots.
This told me the number of slots that each subject should have for my example is three [3]:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image7-1715274461.png/d917c7c59d5b66cf2219a2c9f1650088.jpg)
In Part 5, I created a table where each subject appeared three times (i.e. the number of times given by Subject_Slots).
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image8-1715274478.png/2a017b84b1e503112bcfaf1e5561eae2.jpg)
In Part 6, I randomised the order of the slots ready to add to the timetable:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image12-1715274671.png/a8ca9f195c1932f5ffa66e4f4ab0c151.jpg)
I need to take a reference copy of the Availability query, which I will call TimeTable:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image10-1715277352.png/03f94ae0ee5843fe6277f88ac9049f8e.jpg)
I need to unpivot the day data, but as I described in Part 3, unpivoting will not include the data with null values. These values are vital here, as they are the timeslots I need to fill. I need to replace null with zero [0] for all the day columns. I select all the day columns and right-click to choose ‘Replace Values’:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image11-1715277420.png/cafddaaa14f7a8cff38cb107d6f4fbf2.jpg)
I right-click again and choose to ‘Unpivot Only Selected Columns’:
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image12-1715277437.png/b90d0447b5e10710d29d56fc0f7c7391.jpg)
This gives me all the data in a format that I can use to merge with Random_Subject, but I need to allocate numbers to the slots.
![](http://sumproduct-4634.kxcdn.com/img/containers/main/./image13-1715277472.png/32061c33de06fa20fadf085e860e7280.jpg)
Next time, I will continue to transform this data by numbering the slots.
Come back next time for more ways to use Power Query!