Accumulation Function in Report

I am using LibreOffice Base 7.4 to build a database and I am trying to get a report that uses the Accumulate function in a Group Footer to show the total of a particular field in the detail

When I run the report I find that some groups have a total and others the field is blank

This appears to be related to different values in the “Type” field

Is it the SQL the report uses that is causing this?

I have uploaded my ODB file for reference
Events DEV.odb (31.8 KB)

Many thanks


You are trying to add empty fields. Result of fields with content and empty fields will be NULL (nothing).
Events DEV.odb (37.9 KB)
Have a look at the SQL code of the report:

"EventTransactions"."Paid in",
"EventTransactions"."Paid out"

changed to

COALESCE("EventTransactions"."Paid in",0) AS "Paid in", 
COALESCE("EventTransactions"."Paid out",0) AS "Paid out"

So every field will contain a number, not NULL.
In the second report the ‘0’-values aren’t shown:
Properties → General → Conditional Print Expression → ["Paid in"] > 0
Properties → General → Conditional Print Expression → ["Paid out"] > 0

Thank you very much Robert.