返回表的Oracle过程或函数

Question

如何使过程或函数返回SELECT的结果集，就像我直接进行SELECT操作一样？

Answer 1

因为，

1. 功能：创建一个pipelined功能，并使用它作为表函数。

实施例：

-- Create the types to support the table function. 
DROP TYPE t_tf_tab; 
DROP TYPE t_tf_row; 

CREATE TYPE t_tf_row AS OBJECT (
    id   NUMBER, 
    description VARCHAR2(50) 
); 
/

CREATE TYPE t_tf_tab IS TABLE OF t_tf_row; 
/

-- Build the table function itself. 
CREATE OR REPLACE FUNCTION get_tab_tf (p_rows IN NUMBER) RETURN t_tf_tab AS 
    l_tab t_tf_tab := t_tf_tab(); 
BEGIN 
    FOR i IN 1 .. p_rows LOOP 
    l_tab.extend; 
    l_tab(l_tab.last) := t_tf_row(i, 'Description for ' || i); 
    END LOOP; 

    RETURN l_tab; 
END; 
/

-- Test it. 
SELECT * 
FROM TABLE(get_tab_tf(10)) 
ORDER BY id DESC; 

     ID DESCRIPTION 
---------- -------------------------------------------------- 
     10 Description for 10 
     9 Description for 9 
     8 Description for 8 
     7 Description for 7 
     6 Description for 6 
     5 Description for 5 
     4 Description for 4 
     3 Description for 3 
     2 Description for 2 
     1 Description for 1 

10 rows selected. 

Example Source

步骤：SYS_REFCURSOR作为OUT参数。