Result Sets from Stored Procedures In Oracle

答案：


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; 
/
examples for SQLPlus, Pro*C, Java/JDBC, ODBC, ADO/ASP, DBI Perl and OCI follow: 
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@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

  And now, for a full ASP

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