How to replace a table name with an item value in report region SQL query?

Question

I've got a SQL query in a report region that goes like this:
SELECT :P30_HIDDEN FROM v_dms_dataset
GROUP BY :P30_HIDDEN
P30_HIDDEN is populated from a textfield input. Why doesn't this work, and is there a way to achieve what I'm trying to do here? I really need the ability to dynamically generate SQL queries in this way.

Answer 1

Ben - you could either:
1. case when :P30_HIDDEN = 'COL1' then col1 else ... end
in order to determine which column to select (only really useful if you have a small number of predetermined columns to select from), or
2. generate the SQL dynamically.
Set the report region to SQL Query (PL/SQL function body returning SQL query), then have something like:
declare
l_sql VARCHAR2(4000);
begin
l_sql := 'SELECT ' || :P30_HIDDEN || ' FROM v_dms_dataset
GROUP BY ' || :P30_HIDDEN;
return l_sql;
exception
etc.
end;
John.