How to check for NULL values when using the SUM function in SSRS

Question

By default, the SUM function in SSRS excludes NULLs. I want to be able to check for ANY NULL values in the details group and throw an error in the summary group. In the details view I use this to check for NULLS:

=IIF(IsNothing(Fields!EquityPrice.Value)) ,"#Error", Fields!EquityPrice.Value*Fields!EquityShares.Value)

This works as desired.

When I use this in my summary section, it ignores the NULLS and returns the SUM of the non-null values. I want to return "#Error" instead:

=IIF(IsNothing(SUM(Fields!EquityPrice.Value))) ,"#Error", SUM(Fields!EquityPrice.Value*Fields!EquityShares.Value))

I have tried eliminating the SUM in the "IsNothing" expression but to no avail. Any help would be appreciated. Thanks in advance!

Answer 1

So just to confirm, if there is at least one NULL value in a group, #Error should be displayed?

You can use the following for the Summary expression:

=IIf(Sum(IIf(IsNothing(Fields!EquityPrice.Value),1,0)) > 0
  , "#Error"
  , Sum(Fields!EquityPrice.Value * Fields!EquityShares.Value))

This creates a count of NULL values - if that count is greater than zero, return #Error.

I made a simple report to test:

This uses your expression at the detail level and mine at the summary. Errors for the group with one NULL value as required: