Dynamically write data to a column named in a table

Question

I'd like to write a query that will look up a code, aggregate some data based on the results of that lookup, and store the result in a column named in the lookup table. This isn't real clear; I need an example.
pseudo code:
lookup_table(target_column, lookup_code)
values('target_col_1', 'A')
values('target_col_2', 'B')
select target_column as target ,
lookup_code as code
from lookup_table
for each row {
update results_table r
set target =(
select sum(somecol),
pk_id
from source_table src
where code_col = code
where r.pk_id = src.pk_id
Does this make any sense?

Answer 1

End-User wrote:
I'd like to write a query that will look up a code, aggregate some data based on the results of that lookup, and store the result in a column named in the lookup table.Storing code or parts of code in database tables is a really bad idea.
{message:id=10590811}
You will need to construct the SQL dynamically, which is difficult, error prone and resource intensive if it runs.
http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/dynamic.htm#LNPLS011