How to return a CTE as REFCURSOR from an Oracle stored procedure?

Question

I tried to modify an Oracle stored procedure to use a CTE instead of a simple Select Statement.

My procedure looked like this:

Create or replace Myproc ( MyRefCursor  IN OUT SYS_REFCURSOR)
as
begin
    Open MyRefCursor for
        Select * from ...something ...;


end;
/

I rewrote this query:

   Select * from ...something ...;

As this CTE:

with MyCTE As (
    ... ;
)
Select * from MyCTE;    

Opening a cursor this way does not work:

Open MyRefCursor for
with MyCTE As (
    ... ;
)
Select * from MyCTE;    

Nor does this:

with MyCTE As (
    ... ;
)
Open MyRefCursor for
Select * from MyCTE;    

Answer 1

Since the CTE is part of the same SQL statement, it should not contain a semicolon.

So, there should be no semicolon on the second line of the third block or the third line of the fourth block. The fifth block does not have a contiguous SQL statement.

Answer 2

A complete very basic example using a stored procedure without input parameter:

Some demo data:

CREATE TABLE DEMO(
    id NUMBER(10),
    type NUMBER(10),
    code varchar2(20)
);

Insert INTO DEMO values (1, 0, 'a');
Insert INTO DEMO values (2, 0, 'b');
Insert INTO DEMO values (3, 0, 'c');
Insert INTO DEMO values (4, 1, 'd');
Insert INTO DEMO values (5, 1, 'e');
Insert INTO DEMO values (6, 1, 'f');

SELECT * from DEMO;

Now a simple stored procedure using a trivial CTE:

create or replace procedure return_from_simple_cte
(
    MyRefCursor IN OUT SYS_REFCURSOR
)
AS
BEGIN
    Open MyRefCursor for
    WITH My_CTE AS(
        SELECT * FROM DEMO WHERE Type = 1
    )
    Select * FROM My_CTE;


END;
/

And finally a test call for sqlplus or TOAD

VAR R REFCURSOR
EXEC return_from_simple_cte (:R)
PRINT r

Background to this question:

I did the transformation of the Select-statement to CTE on SQL-Server an I wanted to add row-numbers to the result. I simply forget that add an alias to the *

create or replace  PROCEDURE TEChange
(
    MyRefCursor    IN OUT SYS_REFCURSOR
    ,p_TERefnr    NUMBER
)
AS
BEGIN
    Open MyRefCursor for 
    WITH TE_CTE AS (
        SELECT TeRefnr
        FROM vSYSTE
        WHERE TERefnr <> p_TERefnr
    )
    Select
         ROW_NUMBER() over(order by TERefnr)  Nr, 
        t.* 
    from TE_CTE t;
END;
/    

nonreursive CTEs seem to help to migrate from SQL-Server to Oracle, but there are some minor syntax differences.