How to calculate with criteria of blank item?

[My_Rebecca]

 count({<[Customer Complaint_On-time/Late]={'On-time'},[Customer Complaint_Location]={'SLC SZ'},len([Customer Complaint_Forwarder Name])=0>}[Customer Complaint_On-time/Late])

how to correct this expression? I only want to calculate when the column of "Forwarder Name" is blank, the count of On-time/Late, thanks.

Datasource:

[BrunPierre]

Try

[Customer Complaint_Forwarder Name]={"=Len(Trim([Customer Complaint_Forwarder Name]))=0"}

[My_Rebecca]

@BrunPierre sorry, the result is not correct.

could you please have more look on this question?

[My_Rebecca]

Is there anyone who could help me? thanks.

[BrunPierre]

Post the data in a flat file and the anticipated output in that case.

[zhaofeng]

Try this

 count({<[Customer Complaint_On-time/Late]={'On-time'},[Customer Complaint_Location]={'SLC SZ'},[Customer Complaint_Forwarder Name]={''}>}[Customer Complaint_On-time/Late])

[My_Rebecca]

@zhaofeng I have tried before, like in Excel, but it doesn't work.

[My_Rebecca]

@BrunPierre dear, I have solved in another way, thanks.