Oracle 中 table 函数的应用浅析

SELECT *
 FROM TABLE (myfunction (CURSOR (SELECT *
         FROM mytab)));

CREATE MATERIALIZED VIEW sum_sales_country_mv
BUILD IMMEDIATE
REFRESH COMPLETE
ENABLE QUERY REWRITE
AS
SELECT SUBSTR (s.calendar_month_desc, 1, 4) YEAR, c.country_id country,
   SUM (sum_amount_sold) sum_amount_sold
 FROM sum_sales_month_mv s, customers c
 WHERE s.cust_id = c.cust_id
  AND c.country_id IN ('US', 'UK', 'FR', 'ES', 'JP', 'AU')
GROUP BY SUBSTR (s.calendar_month_desc, 1, 4), c.country_id

CREATE TYPE sum_sales_country_t_tab AS TABLE OF sales_country_t;

CREATE TYPE sales_gender_t AS OBJECT (
 YEAR    VARCHAR2 (4),
 country_id  CHAR (2),
 cust_gender  CHAR (1),
 sum_amount_sold NUMBER
);

CREATE TYPE sum_sales_gender_t_tab AS TABLE OF sales_gender_t;

CREATE TYPE sales_roll_t AS OBJECT (
 channel_desc  VARCHAR2 (20),
 country_id  CHAR (2),
 sum_amount_sold NUMBER
);

CREATE TYPE sum_sales_roll_t_tab AS TABLE OF sales_roll_t;

SELECT object_name, object_type, status
 FROM user_objects
 WHERE object_type = 'TYPE';

CREATE OR REPLACE PACKAGE cursor_pkg
I TYPE sales_country_t_rec IS RECORD (
  YEAR    VARCHAR (4),
  country   CHAR (2),
  sum_amount_sold NUMBER
 );
 TYPE sales_gender_t_rec IS RECORD (
  YEAR    VARCHAR2 (4),
  country_id  CHAR (2),
  cust_gender  CHAR (1),
  sum_amount_sold NUMBER
 );
 TYPE sales_roll_t_rec IS RECORD (
  channel_desc  VARCHAR2 (20),
  country_id  CHAR (2),
  sum_amount_sold NUMBER
 );
 TYPE sales_country_t_rectab IS TABLE OF sales_country_t_rec;
 TYPE sales_roll_t_rectab IS TABLE OF sales_roll_t_rec;
 TYPE strong_refcur_t IS REF CURSOR
  RETURN sales_country_t_rec;
 TYPE row_refcur_t IS REF CURSOR
  RETURN sum_sales_country_mv%ROWTYPE;
 TYPE roll_refcur_t IS REF CURSOR
  RETURN sales_roll_t_rec;
 TYPE refcur_t IS REF CURSOR;
END corsor_pkg;

CREATE OR REPLACE FUNCTION table_ref_cur_week (cur CURSOR.refcur_t)
 RETURN sum_sales_country_t_tab
IS
 YEAR    VARCHAR (4);
 country   CHAR (2);
 sum_amount_sold NUMBER;
 objset   sum_sales_country_t_tab := sum_sales_country_t_tab ();
 i     NUMBER     := 0;
BEGIN
 LOOP
-- Fetch from cursor variable
  FETCH cur
  INTO YEAR, country, sum_amount_sold;
  EXIT WHEN cur%NOTFOUND;
      -- exit when last row is fetched
-- append to collection
  i := i + 1;
  objset.EXTEND;
  objset (i) := sales_country_t (YEAR, country, sum_amount_sold);
 END LOOP;
 CLOSE cur;
 RETURN objset;
END;
/

CREATE OR REPLACE FUNCTION table_ref_cur_strong (cur cursor_pkg.strong_refcur_t)
 RETURN sum_sales_country_t_tab PIPELINED
IS
 YEAR    VARCHAR (4);
 country   CHAR (2);
 sum_amount_sold NUMBER;
 i     NUMBER  := 0;
BEGIN
 LOOP
  FETCH cur
  INTO YEAR, country, sum_amount_sold;
  EXIT WHEN cur%NOTFOUND;     -- exit when last row fetched
  PIPE ROW (sales_country_t (YEAR, country, sum_amount_sold));
 END LOOP;
 CLOSE cur;
 RETURN;
END;
/

CREATE OR REPLACE FUNCTION table_ref_cur_row (cur cursor_pkg.row_refcur_t)
 RETURN sum_sales_country_t_tab PIPELINED
IS
 in_rec cur%ROWTYPE;
 out_rec sales_country_t := sales_country_t (NULL, NULL, NULL);
BEGIN
 LOOP
  FETCH cur
  INTO in_rec;
  EXIT WHEN cur%NOTFOUND;    -- exit when last row is fetched
  out_rec.YEAR := in_rec.YEAR;
  out_rec.country := in_rec.country;
  out_rec.sum_amount_sold := in_rec.sum_amount_sold;
  PIPE ROW (out_rec);
 END LOOP;
 CLOSE cur;
 RETURN;
END;
/

CREATE OR REPLACE FUNCTION gender_table_ref_cur_week (cur cursor_pkg.refcur_t)
 RETURN sum_sales_gender_t_tab
IS
 YEAR    VARCHAR2 (4);
 country_id  CHAR (2);
 cust_gender  CHAR (1);
 sum_amount_sold NUMBER;
 objset   sum_sales_gender_t_tab := sum_sales_gender_t_tab ();
 i     NUMBER     := 0;
BEGIN
 LOOP
  FETCH cur
  INTO YEAR, country_id, cust_gender, sum_amount_sold;
  EXIT WHEN cur%NOTFOUND;    -- exit when last row is fetched
  i := i + 1;
  objset.EXTEND;
  objset (i) :=
   sum_sales_gender_t (YEAR, country_id, cust_gender, sum_amount_sold);
 END LOOP;
 CLOSE cur;
 RETURN objset;
END;
/

SELECT *
 FROM TABLE (table_ref_cur_week (CURSOR (SELECT *
           FROM sum_sales_country_mv)));
SELECT *
 FROM TABLE (table_ref_cur_strong (CURSOR (SELECT *
            FROM sum_sales_country_mv)));
SELECT *
 FROM TABLE (table_ref_cur_row (CURSOR (SELECT *
           FROM sum_sales_country_mv)));
SELECT *
 FROM TABLE (table_ref_cur_week (CURSOR (SELECT *
           FROM sum_sales_country_mv
           WHERE country = 'AU')));