Re: Result Set returned from a Stored Procedure

From: Thomas Kyte <tkyte_at_us.oracle.com>
Date: Fri, 12 Mar 1999 18:31:41 GMT
Message-ID: <36eb5d8a.2655047@192.86.155.100>

A copy of this was sent to "Corné Brouwers" <bware_at_knoware.nl> (if that email address didn't require changing) On Fri, 12 Mar 1999 16:37:31 +0100, you wrote:

>
>Mladen Gogala wrote in message <7c9e12$q82$1_at_nnrp1.dejanews.com>...
>>In article <7c8hk3$imr$1_at_remarQ.com>,
>> "Dorel Baluta" <dbaluta_at_atex.com> wrote:
>>> Does anyone know a workaround to return a result set from a stored
>procedure
>>> in Oracle ? Thanks.
>>>
>>>
>>Result sets in Oracle are called cursors. You can declare variable of
>>type REF CURSOR, open it and return it.
>>
>>Mladen Gogala
>
>
>Is this REF CURSOR variable useable when the stored procedure is called from
>ODBC?
>Corné
>
>

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;
}

The following is thanks to micro_at_work.org (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  

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

--
http://govt.us.oracle.com/ -- downloadable utilities  

---

Opinions are mine and do not necessarily reflect those of Oracle Corporation Received on Fri Mar 12 1999 - 12:31:41 CST