Create SQL string, PL/SQL

Question

Hi,
In my application I have a selectList component, called P1_SELECTLIST. When a user chooses a value, say, 'Car,' I would like my report to return allvalues contained in subclasses of object type 'Car.' I have successfully setup a hierarchy table.
Since you cannot use a bind variable for an object type, I have create the following PL/SQL code to create a SQL string, then execute it. I am not sure where in my application this code goes as I have tried to put it as the report source for the page but have had no success. Perhaps it needs to be created as a separate process?
Thanks.
DECLARE
p1_string VARCHAR2(30);
BEGIN
p1_string:=
'SELECT p.show() FROM ItemHierarchy_obj_table p WHERE VALUE(p) IS OF (' || :p1_selectlist || ')';
EXECUTE IMMEDIATE p1_string;
END;

Answer 1

First, you need to make your p1_string variable bigger. You have it defined for 30 characters which is smaller than you SQL string.
Second, Create a Report Region... when you get to step where you can, Enter SQL Query or PL/SQL function returning a SQL Query, enter the following:
DECLARE
  p1_string VARCHAR2(300);
BEGIN
  p1_string:=
'SELECT p.show() FROM ItemHierarchy_obj_table p WHERE VALUE(p) IS OF (' || :p1_selectlist || ')';
  RETURN p1_string;
END;You don't have to execute the query, APEX will take care of that for you.