How can I get this value?

[Daryl_Zernick]

Is there an expression that can be written to get this number? I am trying to get an Action to fire if this number is "0", writing the expression into the "Only if this condition is true" option.

Any help is much appreciated!!!!

Daryl

[WillowMobileSys]

Try this:

COUNT([Related Updates])

 This assume that the name shown in your view is the assigned name of the column.

[Daryl_Zernick]

Hello Willow,

The view shown is the system generated information, showing that the child table, Updates, has 0 related records to the ID number. Therefore, using your suggestion, I believe the proper expression is "COUNT([ID])=0" which gives me the error "COUNT function is used incorrectly." 

Thank you for the suggestion!

Daryl

[mateo]

Hi
I am not sure but give it a try 😉

COUNT(
 REF_ROWS(
  "Related_DataSet", "Ref_col_ID"
 )
)

[Daryl_Zernick]

Thank you Mateo,

My parent table is EEs and my child is Updates. The Ref is the "ID" column. I tried this: COUNT(REF_ROWS("Updates","ID"))=0

No luck.

Thank you though!!

Daryl

[Rafael_ANEIC-PY]

Hello @Daryl_Zernick, did you try the expression that @WillowMobileSys suggested?

[Daryl_Zernick]

Yes. Here was my reply:

Hello Willow,

The view shown is the system generated information, showing that the child table, Updates, has 0 related records to the ID number. Therefore, using your suggestion, I believe the proper expression is "COUNT([ID])=0" which gives me the error "COUNT function is used incorrectly." 

Thank you for the suggestion!

Daryl

[Rafael_ANEIC-PY]

@WillowMobileSys expression is correct for obtaining the number of child records, you should really try it as it is @Daryl_Zernick 

[Daryl_Zernick]

Below is what I get when trying Willow's expression as written:

Trying it with what I believe is the correct syntax, "COUNT([ID])", generates the following:

[Rafael_ANEIC-PY]

It doesn't work because the name of the column doesn't match, can you share a screenshot of your table column names?

You need to use the name of this column in that expression:

[Daryl_Zernick]

Better yet, I can share the sheet: https://docs.google.com/spreadsheets/d/12JgGVkOjhMRwxjmXd1AKD1TdQVMp_mglN3k0xcMan9s/edit?usp=sharing

[Daryl_Zernick]

What I find curious is that the system generated "View" is fired on this "NOT(ISBLANK([ID]))". Using the same logic for only showing the "Add" option when there are no child records, you would think "ISBLANK([ID])" would work, but it does not... when there are child records, "Add" still shows up.

[WillowMobileSys]

I played with this some in my own app as I happened to be adding a child table in a view.  I also could NOT get the Add button to hide when testing  the count of rows.  I am not yet sure if this is a bug.

I tested by counting both the "related rows"  column - which by the way you can access by "Parent.[Related Rows Column]" as well as creating a SELECT expression.  I also tried using ISBLANK vs ISNOTBLANK.  In none of these cases could I get the Add button to hide.  I believe they should have worked but want to take a closer look.

Obviously, I could use FALSE or TRUE, and it would work just fine.

[Daryl_Zernick]

Thank you Willow! I am also trying a totally different solution that was provided here: https://www.googlecloudcommunity.com/gc/AppSheet-Q-A/Show-quot-Add-quot-if-ID-is-not-already-in-tabl...

This solution seems like it should work, however, I am again lost on the proper COUNT expression for the records in the child table. 

Thanks again for your time on this!!!