An interesting article I read recently:
Result Sets from Stored Procedures In Oracle
A frequently asked question is:
>I'd like to know whether ORACLE supports procedures (functions) which
>returns result sets.
The answer is most definitely yes. 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 [EMAIL PROTECTED] (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
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