How to embed a sub-prodecure call in a SELECT statement in an Oracle 11g PL/SQL stored procedure

Question

I need to figure out a way to embed an Oracle PL/SQL sub-procedure call in a SELECT statement, within another procedure in the same package.

I am using SQLDeveloper 3.0 with an Oracle 11g database.

I have already developed a stored procedure 'acctg_detail_proc()' that generates a detailed list of accounting transactions within a specified period. What I am trying to do is create a summary report procedure 'acctg_summary_proc()' using the detailed data returned by acctg_detail_proc().

Since I am new to PL/SQL, all I have learned so far is how to retrieve the detailed data via a ref cursor, then LOOP through it, FETCHing each individual detail row. I want to figure out how acctg_summary_proc() can substitute that call to acctg_detail_proc() for a table name in a SELECT statement with a GROUP-BY clause. Here is the source code for an anonymous block where I tried to test it:

SET SERVEROUTPUT ON;
DECLARE
    start_date VARCHAR2(50) := '04/01/2012';
    end_date VARCHAR2(50) := '04/30/2012';
    c_acctg_refcur    SYS_REFCURSOR;
BEGIN
  acctg_rpt_pkg.acctg_detail_proc(start_date, end_date, c_acctg_refcur);
  SELECT 
    date_posted,
    debit_acct,
    credit_acct,
    SUM(dollar_amt)
  FROM c_acctg_refcur
  GROUP BY
    date_posted,
    debit_acct,
    credit_acct;
  CLOSE c_acctg_refcur;
END;

When I try to execute this code, I get the following error:

PL/SQL: ORA-00942: table or view does not exist

I realize I could use a nested SELECT statement instead of a table name, but I want to avoid duplication of source code. Is there any way to 'alias' a ref cursor so I can reference its data in a SELECT statement?

Here is some further background info: The called sub-procedure has ~600 lines of code, and selects 40 columns of data from a de-normalized VIEW. The corporate DBAs will not let me create any VIEWs that contain WHERE clauses, so that is not an option for me.

Thanks in advance, Ken L.

Answer 1

It wouldn't perform as well, but to meet your requirements given your limitations, you could use a pipelined result set. Both your original procedure and your new procedure could then use the function. The original one would return the entire results, and the new procedure would wrap the function in a larger query that does the GROUP BY. In this way the core query code would not be duplicated. Here is a pipelined result set example along with two queries using it:

create or replace PACKAGE Example AUTHID Definer AS

Type tRow Is Record (
     F1 Date
   , F2 Date
   );
Type tTable Is Table of tRow;
Function PipelineResult(pDate In Date DEFAULT sysdate) Return tTable Pipelined;

END Example;
/


create or replace PACKAGE BODY Example AS

Function PipelineResult(pDate In Date DEFAULT sysdate) Return tTable Pipelined AS
   vYesterday Date := trunc(sysdate-1);
Begin
  For vRow IN (
      SELECT pDate, vYesterday FROM DUAL
      UNION ALL
      SELECT pDate, vYesterday-1 FROM DUAL
      UNION ALL
      SELECT pDate+1, vYesterday FROM DUAL
  )
  Loop
    Pipe Row(vRow);
  End Loop;
End;

END Example;
/


SELECT * FROM TABLE(Example.PipelineResult);

SELECT F1, count(*) FROM TABLE(Example.PipelineResult) GROUP BY F1;