Cannot summarize this field

[newbie0423]

Crystal XI

I am trying to sum a field but I keep getting a message " this field cannot be summarized". The field I'm trying to total is a formula @turnover and it is written like so:

if OnfirstRecord then
0

Else if Date({v_basic_case_rec_data.cr_prdate}) <> Date(Previous({v_basic_case_rec_data.cr_prdate}))then
0
Else if {v_basic_case_rec_data.room_mnc} <> Previous({v_basic_case_rec_data.room_mnc}) then
0
else
if previous ({@PtOutTime}) > {@roomrdy}then
0
else

IF {v_basic_case_rec_data.room_mnc} = PREVIOUS ({v_basic_case_rec_data.room_mnc})
THEN ({@roomrdy} - PREVIOUS ({@PtOutTime}))/60


Is it the "previous" function that is preventing me from finding the sum of this field?

Thanks in advance for your help

 

[MCuthill]

Newbie043,

In short, "Yes". As Previous() requires the report to be ran prior to evaluating, it cannot be summarized (I think is the "technical" explanation... but 99%+ certain Previous() is your hangup).

To get around this issue, you would need to investigate possiblities with Conditional Running Totals or a similar approach. I cannot recall a time where I have had to use these against a situation with "Previous", but it has allowed me to circumvent this error when it has arisen due to other built-in functions which trigger a "cannot summarize".

Conditional Running Totals generally require three formulas to implement, examples of which I posted recently in the following threads (one of them yours ):
thread767-1712972
thread767-1713174

Please advise should you have further questions.

Cheers!

Mike
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