Oracle
  Home arrow Oracle arrow Page 3 - Working with REF CURSOR in PL/SQL
Dev Shed Forums  
Administration  
AJAX  
Apache  
BrainDump  
DHTML  
Flash  
Java  
JavaScript  
Multimedia  
MySQL  
Oracle  
Perl  
PHP  
Practices  
Python  
Reviews  
Security  
Smartphone Development  
Style-Sheets  
Web Services  
XML  
Zend  
Zope  
Mobile Linux  
App Generation ROI  
IBMŪ developerWorks  
Forums Sitemap  
E-Commerce Hosting  
Linux Web Hosting  
Managed Hosting  
Small Business Hosting  
VPS Hosting  
Weekly Newsletter

 
Developer Updates  
Free Website Content 
 RSS  Articles
 RSS  Forums
 RSS  All Feeds
Write For Us Get Paid  
Request Media Kit
Contact Us  
Site Map  
Privacy Policy  
Support  
 USERNAME
 
 PASSWORD
 
 
  >>> SIGN UP!  
  Lost Password? 
Google.com  
ORACLE

Working with REF CURSOR in PL/SQL
By: Jagadish Chatarji
  • Search For More Articles!
  • Disclaimer
  • Author Terms
  • Rating: starstarstarstarstar / 245
    2007-02-12


    Table of Contents:
  • Working with REF CURSOR in PL/SQL
  • Working with RECORD and REF CURSOR
  • Working with more than one query with the same REF CURSOR
  • Dealing with REF CURSOR in the sub-programs of a PL/SQL block

  • Rate this Article: Poor Best 
      ADD THIS ARTICLE TO:
      error-file:tidyout.log Del.ici.ous error-file:tidyout.log Digg
      error-file:tidyout.log Blink error-file:tidyout.log Simpy
      error-file:tidyout.log Google error-file:tidyout.log Spurl
      error-file:tidyout.log Y! MyWeb error-file:tidyout.log Furl
    Email Me Similar Content When Posted
    Add Developer Shed Article Feed To Your Site
    Email Article To Friend
    Print Version Of Article
    PDF Version Of Article

     
     
    ADVERTISEMENT


    Working with REF CURSOR in PL/SQL - Working with more than one query with the same REF CURSOR
    ( Page 3 of 4 )

    As defined earlier, a REF CURSOR can be associated with more than one SELECT statement at run-time.  Before associating a new SELECT statement, we need to close the CURSOR.  Let us have an example as follows:

    declare
      type r_cursor is REF CURSOR;
      c_emp r_cursor;
      type rec_emp is record
      (
        name  varchar2(20),
        sal   number(6)
      );
      er rec_emp;
    begin
      open c_emp for select ename,sal from emp where deptno = 10;
      dbms_output.put_line('Department: 10');
      dbms_output.put_line('--------------');
      loop
          fetch c_emp into er;
          exit when c_emp%notfound;
          dbms_output.put_line(er.name || ' - ' || er.sal);
      end loop;
      close c_emp;
      open c_emp for select ename,sal from emp where deptno = 20;
      dbms_output.put_line('Department: 20');
      dbms_output.put_line('--------------');
      loop
          fetch c_emp into er;
          exit when c_emp%notfound;
          dbms_output.put_line(er.name || ' - ' || er.sal);
      end loop;
      close c_emp;
    end;

    In the above program, the skeleton looks like the following:

    declare
    .
    .
    Begin
    .
    .
      open c_emp for select ename,sal from emp where deptno = 10;
    .
    .
          fetch c_emp into er;
    .
    .
      close c_emp;
    .
    .
      open c_emp for select ename,sal from emp where deptno = 20;
    .
    .
          fetch c_emp into er;
    .
    .
      close c_emp;
    .
    .
    end;

    From the above skeleton, you can easily understand that every CURSOR is opened, used and closed before opening the same with the next SELECT statement.

    Working with REF CURSOR inside loops

    Sometimes, it may be necessary for us to work with REF CURSOR within loops.  Let us consider the following example:

    declare
      type r_cursor is REF CURSOR;
      c_emp r_cursor;
      type rec_emp is record
      (
        name  varchar2(20),
        sal   number(6)
      );
      er rec_emp;
    begin
      for i in (select deptno,dname from dept)
      loop
        open c_emp for select ename,sal from emp where deptno = i.deptno;
        dbms_output.put_line(i.dname);
        dbms_output.put_line('--------------');
        loop
          fetch c_emp into er;
          exit when c_emp%notfound;
          dbms_output.put_line(er.name || ' - ' || er.sal);
        end loop;
        close c_emp;  
      end loop;
    end;

    As you can observe from the above program, I implemented a FOR loop as follows:

      for i in (select deptno,dname from dept)
      loop
          .
          .
      end loop;

    The above loop iterates continuously for each row of the "dept" table.  The details of each row in "dept" (like deptno, dname etc.) will be available in the variable "i."  Using that variable (as part of the SELECT statement), I am working with REF CURSOR as follows:

        open c_emp for select ename,sal from emp where deptno = i.deptno;

    The rest of the program is quite commonplace.



     
     
    >>> More Oracle Articles          >>> More By Jagadish Chatarji
     

       

    ORACLE ARTICLES

    - Oracle's Turn to Play in the Sun
    - Implementing and Using Oracle`s Restore Poin...
    - Tuning PL/SQL Code
    - Debugging PL/SQL Code
    - Testing PL/SQL Code
    - Working With PL/SQL Code
    - Conditional Compilation for Oracle Database ...
    - Compile-Time Warnings for Oracle DB 10g
    - Compiling PL/SQL Code for an Oracle Database
    - Troubleshooting PL/SQL Code
    - Managing PL/SQL Code
    - Data Manipulation and More for HTML DB Appli...
    - Oracle Database Fundamentals
    - Adding Processes to HTML DB Applications
    - Adding Computations, Processes, and Validati...





    © 2003-2009 by Developer Shed. All rights reserved. DS Cluster 3 Hosted by Hostway
    For more Enterprise Application Development news, visit eWeek