apex select list, get user data - oracle-apex

Question

I've created a select list item and need to reference this list on another page. how do i get the user input, place it in a variable that can be used to calculate the total value of the selected item on another page?
code for the select list which is displayed on a report to allow for amount to be stated:
select item_id,
itemname,
item_price,
apex_item.hidden(1, item_id) ||
apex_item.hidden(2, item_price) ||
apex_item.select_list(
p_idx => 3,
p_value => nvl(null,'item'),
p_list_values => '1,2,3,4,5,6,7,8,9,10',
p_show_null => 'YES',
p_null_value => 0,
p_null_text => '0',
p_item_id => 'f03_#ROWNUM#',
p_item_label => 'f03_#ROWNUM#',
p_show_extra => 'NO') "item"
from item
the select to display the sum will look something like this:
select itemname,
item_price,
'select list value',
('select list value'* item_price) as sum
from item
how do i get the chosen amount from the select list?
Thanks

Answer 1

Oracle APEX has package APEX_APPLICATION which contains collections with names from G_F01 to G_F50. When you use any function from apex_item to create an item inside a report, you pass a number into p_idx parameter. In your example it is 3 for the select list. This value corresponds to one of collections mentioned above - G_F03 in this case.
All values from user's input are passed to these collections after the submit. So you can to write in the after submit process following code:
for i in apex_application.g_f01.first .. apex_application.g_f01.last loop
insert into my_table (id, new_value)
values (apex_application.g_f01(i), apex_application.g_f03(i));
end loop;
This code shows how to insert values from user's input into my_table. Note, that these collections contain only rows changed by user. If a user gets a report with 10 rows and changes 3 of them, each collection will have 3 elements.
Also, APEX has APEX_COLLECTION API to store temporary data.
For more information, see in the documentation: APEX_APPLICATION, APEX_COLLECTION.
UPD.
There are two ways to work with the data further - using a table or APEX_COLLECTION. I have never worked with APEX_COLLECTION, so here is an example with a table.
If you use a table to store temporary data, you need columns for ID, user's name and data (data from the Select List in your example). On the page with the report you need to do this after the submit:
delete from my_table where user_name = :APP_USER;
for i in apex_application.g_f01.first .. apex_application.g_f01.last loop
insert into my_table (id, new_value, user_name)
values (apex_application.g_f01(i), apex_application.g_f03(i), :APP_USER);
end loop;
On the next page, where you need to use this data, you create the following report:
select t.new_value, ...
from my_table t, ... <other tables>
where t.user_name = :APP_USER
and t.id = ...
and <other conditions>