Limit duplicates display in a collection

[Thomas_b]

Hi there.

I am creating a conference app event, and I’d like to list all talks which fall under the same theme. In this example, only the sessions with the filter ‘The Social Power of Cycling’ are shown.

However, my database lists all the composition of all talks. It means that a speaker can appear several times, and that the same talk appears 4-5 times (as there are 4-5 speakers in each of them). Consequently, on the app display’s screenshot, we can see that sessions are shown several times (e.g. 8.2 Cycling to school).

How is it possible to show only 1 talk, even if it is listed 4-5 times in the database?

Thanks in advance !

[Nicolas_Joseph]

Hi @Thomas_b

I would recommend you to have a specific table for Sessions and another one for Contributors.
Each session would be unique which easily allows you to create a list of sessions without duplicates.
We could also create a relation between these two tables to display the speakers and/or moderators (for example, when the user click on the session card).

The result would be something like this (according to your screenshot):

How to get there?

Contributors table

Sessions table

Basicaly, I just added each information in the relevant table.
Of course I’m not familiar with your data, but the logic here is the following - feel free to ajust:

• each session has:
  • a specific ID (1,2, 1,3 ans so on)
  • a title
  • and a description.
• on the other hand, each contributor as:
  • a name
  • a function for the session
  • and the session ID of the session (s)he will be a contributor to.

The only curious thing is the Contributors (relation) column so here is the setup:

In the Layout, we use the Sessions table as the source of the list:

And, as a bonus, you can use the relation to display the list of people for the specific session just like this:

This approach is - in my opinion - way more logic from a data perspective. Information are isolated inside specific tables and you use the power of computed columns in Glide to create relations between them

Without changing the structure

If you have not the ability to change the structure of your tables, there is an option for getting only one value displayed for each session as you asked.
I’ll showcase it based on the Contributors table already mentioned.

Create 4 new colums:

1. Row ID (Row ID). In order to get a unique value for each row.
2. All rows of this session (Query). To define the first row found for each session ID:
   
   
3. Row ID of first row (Single Value). To obtain the Row ID of this first row:
   
   
4. Is first row? (If → Then → Else). To test if the actual row is - indeed - the first row:
   
   

And in the setup of the collection (your list), you’ll just have to apply a filter, to only keep row where Is first row? is TRUE:

As already mentioned, I’m not a fan of this approach in your case . However, it’s very helpful is some situations! Now you know this way of doing too.

Let us know if that helps!