How test a empty relationship

[Amber]

Hi,
I want to display a list of all the “Midwifes” that have no user assigned to.

Collections:
Users, have a relationhip to many Midwifes
Midwives, have a relationship to one User

List resultwanted: all Midwifes that have no User assigned.

It seem simple but I just cannot figure out how to do…
Thanks for help!

https://previewer.adalo.com/7a44da97-6643-465e-aa3f-ee5b18e26521?_gl=1*1tk3gjv*_ga*NTYwODUyNjAwLjE2Njg5NjMwOTY.*_ga_SWT45DV35L*MTY3Mjg2MjM3NC44NS4xLjE2NzI4NzU0MzMuNi4wLjA.

[Flawless]

Add a custom filter to your list of All Midwives.

List of Midwives > All

Custom filter where Midwives > User > Email > is equal to > empty.

[Amber]

This is what I did but it doesn’t work. I don’t understand why.

In the picture: I created a simple Apps Test with two lists: the top list have no filter and the bottom list have this Midwives>User>Email > is equal to > empty filter. I expect to get only three results in the second list but I got the same Top list.

[dilon_perera]

Hi @Amber,

What Flawless said should work! I tested this too but unfortunately it didn’t worked. I guess this is a bug in Adalo side because after grouping the components inside the list and putting the condition there worked!

Check here : Midwifes that have no user assigned.mp4 - Google Drive

Thank you

[lakakhan]

Test for Empty Relations
Apkcor

1. The exists construct returns true if the argument subquery is nonempty.
2. Find all customers who have a loan and an account at the bank. select cname. from borrower. where exists (select * from depositor. where depositor.cname = borrower.cname)