Query Search Select List

Question

I have a search form with multiple search list. When the user selects an option from the search list I want my other select list to filter based on the first dropdown option selected.
Web App name "Listings"
First Dropdown list is "Animal" - option 1 "Elk", option 2 "Deer", Option 3 "Bear".
Second Dropdown list is "City" - option 1 "Steamboat", option 2 "Brush", Option 3 "Strasburg".
From the first dropdown list the user would choose animal. I'm trying to accomplish the second dropdownlist to refresh and only display what City the animal would reside in. Can this be done? How would one do this?

Answer 1

then v_where_clause := v_where_clause || c_isnull;If the parameter is not supplied then are you sure you want to match to null?
Why not something like:
if in_customer_id is not null then
c_where_clause := c_where_clause||' WHERE customer_id = :customer_id';
else
  c_where_clause := c_where_clause||' WHERE 1=1 or :customer_id is null';
end if;
if in_account_no is not null then
c_where_clause := c_where_clause||' AND account_no = :account_no'
else
  c_where_clause := c_where_clause||' AND 1=1 or :account_no is null';
end if;Then your list of values in the using clause is always constant.
This does get complicated if your in parameters are used multiple times in different ways throughout the query you are building up.
Ben