Subtracting lists not working

[Mayank_Gupta]

I have the following formula for subtracting lists:

(Sheet1[Patient Name]-Target Table[Entry])

Following is the screenshot of Table Sheet1

Following is the screenshot of Table Target Table

I am using the above mentioned formula in a Column Type Enum List. But it is giving me the wrong output… The output it gives me is the following

Instead of subtracting, it is adding both the lists in the dropdown, items of Sheet1 are preselected.

I don’t know why it is happending

[Marc_Dillon]

Judging by your last screenshot, I’m guessing you used the expression in Initial Value ? If that is the case, it is doing exactly what you told it to do. What do you want it to do?

[Mayank_Gupta]

Hi, thanks for replying. Yes I want it to show only those patient names from column “patient name” of table “Sheet1” which are not present in column “entry” of table “target table”. So, in above example, my enum list should only show (that also unchecked) the following patient names:
Bill Thomas
Tom cather
Tom
Sue

[Marc_Dillon · Accepted solution]

Initial Value is not the appropriate place to put your expression then.

help.appsheet.com

Dropdown from Valid_If

How to create a dropdown that depends on a particular list of values.

help.appsheet.com

App Formulas and Initial Values

How you can set app formulas and initial values to dynamically assign values.

[Mayank_Gupta]

Thanks Marc, these helped a lot in clearing the problem. My basics were not clear.

[Matheus_Souza]

I know this is an old thread. But today I'm not able to perform a list subtraction. I'm using the following formula:

[VISIBILIDADE NÍVEL]-select(USUÁRIOS MANUT[NÍVEIS DE ACESSO],[EMAIL ACESSO]=USEREMAIL())

The result I get is equal to the [VISIBILIDADE NÍVEL] Enum list, even if its values are in the SELECT result.

Is there something I am missing?

[Matheus_Souza]

A "SPLIT" on the [VISIBILIDADE NÍVEL] solved it!