Question

I need an update query to set the null values with another value in the same group

for example

 Table
    filed1   filed2      filed3
    1          e         1/1/2009
    1          e         null
    1          e         1/1/2009
    2          f         2/2/2009
    2          f         2/2/2009
    2          f         null
    3          g         3/3/2009
    3          g         null

Expected Result

filed1   filed2      filed3
1          e         1/1/2009
1          e         1/1/2009
1          e         1/1/2009
2          f         2/2/2009
2          f         2/2/2009
2          f         2/2/2009
3          g         3/3/2009
3          g         3/3/2009

Answer 1

-- note table1 is your table

UPDATE t1 set t1.filed3 = t2.filed3 
from table1 t1, table1 t2
where t1.filed3 is null
and t2.filed3 is not null 
and t1.filed2 = t2.filed2 and 
t1.filed1 = t2.filed1