SUM of column in VIEW

[Pedro Cuica]

hi guys !!

i have 3 tables where i'm joining the information to create a view. when the view is created, appears something like this:

DATE FIELD1 FIELD2 FIELD3
20100901 code1 name1 number1
20100901 code2 name2 number2
20100901 code3 name3 number3
20100902 code4 name4 number4
20100901 code5 name5 number5
20100902 code6 name6 number6


now what i need, is to SUM the field3, by date, and then divide the field3 by the SUM result and insert it in a field4.

i've tryed so many ways, but nothing works, how can i fix this??

tku