Re: HELP: Can Oracle Strored Procs./Funcs. return Result Sets ?

From: Thomas Kyte <tkyte_at_us.oracle.com>
Date: Wed, 09 Jun 1999 11:44:12 GMT
Message-ID: <37625385.85611833@newshost.us.oracle.com>

A copy of this was sent to Arman Ali Anwar <arman.anwar_at_mci.com> (if that email address didn't require changing) On Tue, 08 Jun 1999 22:14:13 GMT, you wrote:

>TIA, and could you kindly send all replies to arman.anwar_at_wcom.com
>
>Arman.

In short, it'll look like this:

create or replace function sp_ListEmp return types.cursortype as

    l_cursor types.cursorType;
begin

    open l_cursor for select ename, empno from emp order by ename;     return l_cursor;
end;
/

With 7.2 on up of the database you have cursor variables. Cursor variables are cursors opened by a pl/sql routine and fetched from by another application or pl/sql routine (in 7.3 pl/sql routines can fetch from cursor variables as well as open them). The cursor variables are opened with the privelegs of the owner of the procedure and behave just like they were completely contained within the pl/sql routine. It uses the inputs to decide what database it will run a query on.

Here is an example:

create or replace package types
as

    type cursorType is ref cursor;
end;
/  

create or replace function sp_ListEmp return types.cursortype as

    l_cursor types.cursorType;
begin

    open l_cursor for select ename, empno from emp order by ename;  

    return l_cursor;
end;
/    

REM SQL*Plus commands to use a cursor variable  

variable c refcursor
exec :c := sp_ListEmp
print c

---

and the Pro*c to use this would look like:

static void process()
{
EXEC SQL BEGIN DECLARE SECTION;
    SQL_CURSOR my_cursor;

    VARCHAR     ename[40];
    int         empno;

EXEC SQL END DECLARE SECTION;       EXEC SQL WHENEVER SQLERROR DO sqlerror_hard();  

    EXEC SQL ALLOCATE :my_cursor;  

    EXEC SQL EXECUTE BEGIN
        :my_cursor := sp_listEmp;
    END; END-EXEC;       for( ;; )
    {

        EXEC SQL WHENEVER NOTFOUND DO break;
        EXEC SQL FETCH :my_cursor INTO :ename, empno;
 
        printf( "'%.*s', %d\n", ename.len, ename.arr, empno );

    }
    EXEC SQL CLOSE :my_cursor;
}

And the java to use this could be:

import java.sql.*;
import java.io.*;
import oracle.jdbc.driver.*;

class curvar
{
  public static void main (String args [])

                     throws SQLException, ClassNotFoundException
  {
      String driver_class = "oracle.jdbc.driver.OracleDriver";
      String connect_string = "jdbc:oracle:thin:@slackdog:1521:oracle8";

      String query = "begin :1 := sp_listEmp; end;";
      Connection conn;

      Class.forName(driver_class);
      conn = DriverManager.getConnection(connect_string, "scott", "tiger");

      CallableStatement cstmt = conn.prepareCall(query);
      cstmt.registerOutParameter(1,OracleTypes.CURSOR);
      cstmt.execute();
      ResultSet rset = (ResultSet)cstmt.getObject(1);

      while (rset.next ())
        System.out.println( rset.getString (1) );
      cstmt.close();

  }
}

The following is thanks to marktoml_at_hotmail.com (mark tomlinson)..

If you use ODBC here is a working example, but it requires the use of the 8.0.5.2.0 or later Oracle ODBC driver, and an 8.0.5 server.

'
' 1) Create a form with 1 Text control (Text1) and 1 List Control (List1) and
' 1 Button (btnExecute).
' 2) The only code that you need is a Click method on your button. Here is the Code.
'
'
Private Sub btnExecute_Click()

'PL/SQL Code
'===========
'
'CREATE OR REPLACE package reftest as
' cursor c1 is select ename from emp;
' type empCur is ref cursor return c1%ROWTYPE;
' Procedure GetEmpData(en in varchar2,EmpCursor in out empCur);
'END;
'
'
'CREATE OR REPLACE package body reftest as
'   Procedure GetEmpData
'(en in varchar2,EmpCursor in out empCur) is
'begin
' open EmpCursor for select ename from emp where ename LIKE en;
'end;
'end;
'
     Dim cn As New rdoConnection
     Dim qd As rdoQuery
     Dim rs As rdoResultset
     Dim cl As rdoColumn
     Static Number As Integer
     
     List1.Clear
     Number = 0
     cn.Connect = "uid=scott; pwd=tiger; DSN=MSLANGORL;"
     'enable the MS Cursor library
     cn.CursorDriver = rdUseOdbc
     'Make the connection
     cn.EstablishConnection rdNoDriverPrompt
      
     sSQL = "{call RefTest.GetEmpData(?,?)}"
     
     Set qd = cn.CreateQuery("", sSQL)
          
     qd.rdoParameters(0).Type = rdTypeVARCHAR
     qd(0).Direction = rdParamInputOutput
     qd(0).Value = Text1.Text
     qd.rdoParameters(1).Type = rdTypeVARCHAR

     'Dynamic or Keyset is meaningless here
     Set rs = qd.OpenResultset(rdOpenStatic)

     Do
        Debug.Print
        Debug.Print
        
        Do Until rs.EOF
            For Each cl In rs.rdoColumns
                 If IsNull(cl.Value) Then
                    List1.AddItem "(null)"
                    ' Debug.Print " "; cl.Name; "NULL"; Error trap for
null fields
                Else
                    List1.AddItem cl.Value
                    ' Debug.Print " "; cl.Name; " "; cl.Value;
                End If
            Next
            Debug.Print
            rs.MoveNext
        Loop
     Loop While rs.MoreResults
     cn.Close

End Sub

See http://www.oracle.com/ideveloper/ for my column 'Digging-in to Oracle8i'... Mirrored (and more current) at http://govt.us.oracle.com/~tkyte/

Current article is "Fine Grained Access Control", added June 8'th  

Thomas Kyte                   tkyte_at_us.oracle.com
Oracle Service Industries     Reston, VA   USA

--
Opinions are mine and do not necessarily reflect those of Oracle Corporation Received on Wed Jun 09 1999 - 06:44:12 CDT