如何處理Crystal Reports中的空白字段/變量？

Question

我在我的組頁腳中有以下公式，但在顯示0時遇到問題，如果sample_perc爲空;如果#rt_sample_ordered爲空，則此值爲空。

NumberVar sample_perc := {#rt_sample_ordered}%{@sum_of_sample}; 
if (sample_perc>0)then 
    sample_perc 
else 
    0 

如何在sample_perc爲空時打印0？

Answer 1

If Isnull({#rt_sample_ordered}) Or Isnull({@sum_of_sample}) Then 
    0 
Else If ({#rt_sample_ordered}%{@sum_of_sample}) > 0 Then 
    sample_perc 
Else 
    0