Beware of Zero and Blank (Number Columns)

[Swoopy]

Base on my experience, AppSheet saves blank value when the entry of number columns are deleted and saved in forms. This leaves empty cell (not zero) in the backend tables. At first I think it should be okay (zero should be equal to blank, and vice versa).

However, AppSheet's expression may treats zero value and blank cell in different ways, for example

[Quantity] = 0

If [Quantity] is zero, it outputs TRUE.
If [Quantity] is blank, it outputs FALSE !!!
   but 0+[Quantity] = 0 outputs TRUE although it's blank.

[Quantity] > 0

If [Quantity] is zero, it outputs FALSE.
If [Quantity] is blank, it outputs FALSE.

Blank value always outputs FALSE, in my app settings.

So, be careful and check out the link posted by @Marc_Dillon below (thanks).

[Marc_Dillon]

https://support.google.com/appsheet/answer/11510515?hl=en

[Swoopy]

Thank for the link.

I've never seen a page mentions about cell being saved by forms as empty instead of zero for blank entry. Consistent mode is promoted to be faster processing but give results somewhat may need workarounds. In Legacy mode, we need to be careful if an expression is run on client or server. Also, the link does not mention about results from [blank] in operations like ([blank] + number) or - , x , /. Or may be I overlook some documentation.