I want to process survey results with LibreOffice Calc (for example with data coming from LimeSurvey).

Since some questions were optional, some cells are empty (like `A6`):

![LibreOffice screenshot columns](https://i.stack.imgur.com/IaLDy.png)

I want to answer questions like:

* How many people have given the answer `2`?
* How many people did not respond?

So, I've created a pivot table with `Insert` → `Pivot`:

[![enter image description here](https://i.stack.imgur.com/gntOI.png)](https://i.stack.imgur.com/gntOI.png)

but... I was not able to answer the question "How many people did not respond?" (see `B6`).

![LibreOffice pivot table screenshot empty](https://i.stack.imgur.com/mJ40Q.png)

Actual bug:

* the cell `B6` counting empty cells **is empty**

Expected result:

* the cell `B6` counting empty cells should be `1` (sum of empty cells = `1`)

To fix this problem I have a workaround consisting in creating a "temporary table" and replacing empty cells with something weird like `§ EMPTY VALUE §` to then be able to analyze empty values with my pivot table.

How do you handle empty cells in LibreOffice Calc with a pivot table?

Tested on LibreOffice 6.4.7 on Debian GNU/Linux but I can reproduce on Ubuntu 20.04 Focal Fossa and on other operating systems.

Thank you so much!