Oracle APEX-是否可以在不刷新整个页面的情况下将值提交到会话状态？

Question

I've got a page that has a bunch of Select List items. Each Select List item underneath the next executes an SQL query to retrieve the previous item's value from the session state, and displays a new list based on the result.

I can get everything to work by allowing each Select List item to 'Submit to Page', which refreshes the entire page. Seeing as there are 5+ Select List items, it's not very user-friendly to have the user wait on each refresh.

Is there a way to either get the value from a Select List into the session state without refreshing the page, or for an SQL Query to take the value from the previous Select List item and use it in it's query to display a new list?

Answer 1

I think you are looking for Cascading LOVs. Here is a short example on how to use them.

Let's say you want to have 2 select lists one with departments and one with the employees that work in the selected department. So we need a table DEPARTMENTS(department_id, deparment_name) with all your departments and a table EMP(emp_id, emp_name, department_id) with all the employees and in what department they work in.

Create your first select list named P1_DEPARTMENTS with the List of Values SQL Query like this select department_name, department_id from departments

Now create the second select list named P1_EMPLOYEES using the List of Values SQL Query

select emp_name, emp_id from EMP where department_id=:P1_DEPARTMENTS

Now in the Cascading LOV Parent Item(s) attribute of P1_EMPLOYEES select list you have to select the item that you want to pass as a parent in our case the P1_DEPARTMENTS .

Now when you select a value in the P1_DEPARTMENTS select list the P1_EMPLOYEES select list will refresh and you will get just the employees that work in the selected department.