Ref Cursors... Query

Question

Hello,
I have created the package which uses the ref cursor.
I was able to compile the package.. I was not able to execute this package which calculates the sum of col1
====================================================
create table temp123 (col1 number, col2 varchar2(10), col3 date);
insert into temp123 values ( 1, 'A',sysdate-3);
insert into temp123 values ( 2, 'B',sysdate-2);
insert into temp123 values ( 3, 'C',sysdate-1);
insert into temp123 values ( 4, 'D',sysdate);
commit;
create or replace package asu123 as
type ref_def is record ( a_col temp123.col1%type,b_col temp123.col2%type, c_col temp123.col3%type);
type rec_type is ref cursor return ref_def;
function fun return rec_type;
end;
create or replace package body asu123 as
function fun return rec_type
as
a_rec rec_type;
begin
open a_rec for select * from temp123;
return a_rec;
end;
end;
If I execute the below sql, it will work fine...
select asu123.fun from dual;
COL1 COL2 COL3
1 A 04-NOV-04
2 B 05-NOV-04
3 C 06-NOV-04
4 D 07-NOV-04
=======================================================
Some how I need to execute this query as which sum's the COL1 field.
SELECT NVL (COUNT (*), 0) TOTALCOUNT,NVL (SUM (asu123.ref_def(sum(col1) ), 0) SUM_VALUE from dual;Any one have any inputs on this?. Thanks for your valuable feedback in advance.
--Binny

Answer 1

Either you are using cursor variables to solve the wrong problem or you are using them the wrong way. Consider these two different approaches. First, with REF CURSOR...
SQL> CREATE TABLE temp123 (col1 number, col2 varchar2(10), col3 date)
  2  /
Table created.
SQL> INSERT INTO temp123 VALUES ( 1, 'A',sysdate-3)
  2  /
1 row created.
SQL> INSERT INTO temp123 VALUES ( 2, 'B',sysdate-2)
  2  /
1 row created.
SQL> INSERT INTO temp123 VALUES ( 3, 'A',sysdate-1)
  2  /
1 row created.
SQL> INSERT INTO temp123 VALUES ( 4, 'A',sysdate)
  2  /
1 row created.
SQL> INSERT INTO temp123 VALUES ( 5, 'B',sysdate+1)
  2  /
1 row created.
SQL> INSERT INTO temp123 VALUES ( 6, 'B',sysdate+2)
  2  /
1 row created.
SQL> CREATE OR REPLACE PACKAGE asu123 AS
  2      --  in 9i we can use the predeclared sys_refcursor and skip this bit
  3      TYPE rec_type is ref cursor ;
  4      FUNCTION recs RETURN rec_type;
  5      FUNCTION sums RETURN rec_type;
  6  END;
  7  /
Package created.
SQL> CREATE OR REPLACE PACKAGE BODY asu123 AS
  2      FUNCTION recs RETURN rec_type
  3      AS
  4          a_rec rec_type;
  5      BEGIN
  6          OPEN a_rec FOR SELECT * FROM temp123;
  7          RETURN a_rec;
  8      END recs;
  9      FUNCTION sums RETURN rec_type
10      AS
11          a_rec rec_type;
12      BEGIN
13          OPEN a_rec FOR SELECT col2, COUNT (*) AS totalcount, sum(nvl(col1, 0)) AS sum_value 
14                         FROM temp123
15                         GROUP BY col2;
16          RETURN a_rec;
17      END sums;
18  END;
19  /
Package body created.
SQL> SELECT  asu123.recs FROM dual
  2  /
RECS
CURSOR STATEMENT : 1
CURSOR STATEMENT : 1
      COL1 COL2       COL3
         1 A          05-NOV-04
         2 B          06-NOV-04
         3 A          07-NOV-04
         4 A          08-NOV-04
         5 B          09-NOV-04
         6 B          10-NOV-04
6 rows selected.
SQL> SELECT  asu123.sums FROM dual
  2  /
SUMS
CURSOR STATEMENT : 1
CURSOR STATEMENT : 1
COL2       TOTALCOUNT  SUM_VALUE
A                   3          8
B                   3         13...versus using NESTED TABLE...
SQL> CREATE TYPE my_rec AS OBJECT (col1 number, col2 varchar2(10), col3 date);
  2  /
Type created.
SQL> CREATE TYPE my_tab AS TABLE OF my_rec;
  2  /
Type created.
SQL> CREATE OR REPLACE PACKAGE asu123 AS
  2      FUNCTION recs RETURN my_tab;
  3  END;
  4  /
Package created.
SQL> CREATE OR REPLACE PACKAGE BODY asu123 AS
  2      FUNCTION recs RETURN my_tab
  3      AS
  4          a_rec my_tab;
  5      BEGIN
  6          SELECT my_rec(col1, col2, col3) BULK COLLECT INTO a_rec
  7          FROM   temp123;
  8          RETURN a_rec;
  9      END recs;
10  END;
11  /
Package body created.
SQL> SELECT * FROM table(asu123.recs)
  2  /
      COL1 COL2       COL3
         1 A          05-NOV-04
         2 B          06-NOV-04
         3 A          07-NOV-04
         4 A          08-NOV-04
         5 B          09-NOV-04
         6 B          10-NOV-04
6 rows selected.
SQL> SELECT col2, COUNT (*) AS totalcount, sum(nvl(col1, 0)) AS sum_value
  2  FROM   table(asu123.recs)
  3  GROUP BY col2
  4  /
COL2       TOTALCOUNT  SUM_VALUE
A                   3          8
B                   3         13
SQL> Cheers, APC