Calculated value

[#1]

Hi,

i would like to  insert a calculate value in my set of data.

Customer	Ordertype	Calculate values (e-comCustomer)
luca	A	yes
luca	J	yes
giorgio	G	yes
giorgio	B	yes
paolo	A	no

e-comCustomer: Yes -> at leat once Customer had J or G

ps: note that my set of data come from different connection odbc , but data has same structure/table/attributes

Please How I can set the expression on the script?  Many thanks