2023: Week 43 - Solution



Solution by Tom Prowse and you can download the workflow here.


Step 1 - Combine Inputs

The first step is to create a single table that contains the information from each of our input tables. We have an input for each of the 3 terms and another input with information around the year that the student is in.

First we want to combine the 3 term tables by using an union to 'stack' them on top of each other.


We then want to find the total number of days that a student was present and absent from class. We can use an aggregation step to group by first & last name then sum days present and days absent: 



Finally we want to include the data around which year each student is in. This time we are going to use an inner join on both of the name fields: 


After removing any duplicated fields the table should look like this:




Step 2 - Attendance Rate

Next we want to combine the first and last names so we have a full name field: 

Full Name
[First Name]+" "+[Last Name]

Then we can calculate the attendance rate for each person across the year: 

Year Attendance Rate
ROUND(
100*[Days Present]
/
([Days Present]+[Days Absent])
,2)

We are now ready to find the students with the highest overall attendance. Within a new clean step, we first want to rank each person based on their attendance: 

Rank


We can then use this field to keep only the top value (Rank = 1), then we can remove the additional fields and our first output should look like this: 



For the final output we need to create a new clean step from the step where we calculate the attendance rate. From here we can calculate the percentage ranking by utilising a percentile rank calculation: 

Percentage Rank



We can then use this rank field to filter the value within the top 5%: 


We can then output our second output that looks like this: 



You can download the outputs from here.

After you finish the challenge make sure to fill in the participation tracker, then share your solution on Twitter using #PreppinData and tagging @treamcelhone, @Datajedininja, @JennyMartinDS14 & @TomProwse1

You can also post your solution on the Tableau Forum where we have a Preppin' Data community page. Post your solutions and ask questions if you need any help! 

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