TABLE function to simulate parameterized view

Question

Hi all,
Since view can not have parameters, I tried to used stored procedure to return ref cursor then used TABLE function in select statement to simulate a view with parameters, since it's easy to pass parameters to a stored procedure.
The idea is like this
function foo (p1 int, p2 int)
return sys_ref_cursor
c sys_ref_cursor -- sorry, i forgot the buildin ref cursor name, just used
this as pseudo code
is
open c for select * from table_a where col1=:p1 and col2=p2 using p1, p2;
return c;
end;
select * from table(foo(1,2)) does not work, I know that I can iterate throught
the cursor and pipe it out to a SQL type in function foo, then use TABLE
function in SELECT statement. However, it seems so much coding work. Is it the
only way or do you have better idea?
Thanks in advance.

Answer 1

It is just not correct that you cannot parameterize views.
Nicolas gave you a link above which has an example using a context.
Even before Oracle supported contexts you could have parameterize views using package variables.
SQL> create or replace package pkg_vars as
  2    function get_job return emp.job%type;
  3    procedure set_job (p_job in emp.job%type)
  4  end pkg_vars;
  5  /
Package created.
SQL>
SQL> create or replace package body pkg_vars as
  2    g_job emp.job%type;
  3
  4    function get_job return emp.job%type)
  5    is
  6    begin
  7      return g_job;
  8    end get_job;
  9
10    procedure set_job (p_job in emp.job%type
11    is
12    begin
13      g_job := p_job;
14    end set_job;
15  end pkg_vars;
16  /
Package body created.
SQL>
SQL> create or replace view view_emp1 as
  2  select deptno, count(empno) cnt
  3  from emp
  4  where job = pkg_vars.get_job
  5  group by deptno
  6  ;
View created.
SQL> select distinct job from emp;
JOB
CLERK
SALESMAN
PRESIDENT
MANAGER
ANALYST
5 rows selected.
SQL> exec pkg_vars.set_job('CLERK');
PL/SQL procedure successfully completed.
SQL> select * from view_emp1;
    DEPTNO        CNT
        30          1
        20          2
        10          1
SQL> exec pkg_vars.set_job('MANAGER');
PL/SQL procedure successfully completed.
SQL> select * from view_emp1;
    DEPTNO        CNT
        30          1
        20          1
        10          1
SQL>