Select statement with if condition in cursors

Question

Create procedure test (t1 in varchar2 ,t2 out varchar2)
IS
BEGIN
IF t1 = 'E'
select ENO INTO t2 from emp ;
elsif t1 = 'D'
select DNO INTO t2 from dept ;
end if;
end
how do i write this using cursors

Answer 1

i think i have to go for two cursors Intially i have written like the below codeThis requirement merely made me think of a pure SQL solution - something interesting...
As I mentioned, you likely should be using ref cursors as typically this requirement extends to a client that wants to make a call to Oracle without needing to know SQL or table names, pass parameters, and get a dynamic "+result set+" in response.
In Oracle. this is done using ref cursors. The code will look something like this"
{code}
create or replace procedure FooProc( someVar1 varchar2, someVar2 number, curResult OUT sys_refcursor ) is
begin
case
when someVar1 = someValueA then
open curResult for select * from emp;
when someVar1 = someValueB then
open curResult for select * from emp where empid = someVar2;
.. etc ..
end case;
end;
{code}
This is pretty straight forward stuff - and well explained with examples in the Oracle® Database PL/SQL User's Guide and Reference (http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/sqloperations.htm#sthref139)
You procedure it a tad different in output parameters (and not what one typically would get in a production system), but the concept is the same. If the SQL projection is the same for each cursor, you can use a ref cursor as above - and then simply code a single fetch to get the row's columns, close the cursor, and then return that column values as output parameters.
Edited by: Billy Verreynne to fix the broken Jive s/w that does not understand how to parse a link and show it correctly.. (am getting more and more peeved at the crappiness factor of the new forum s/w)