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REF CURSOR Examples 

The REF CURSOR examples are comprised of the following three Microsoft Visual Basic examples that demonstrate using REF CURSORs.

Sample Description

Retrieving a REF CURSOR Parameter in an OracleDataReader

This example executes a PL/SQL stored procedure that returns a REF CURSOR parameter, and reads the value as an OracleDataReader.

Retrieving Data from Multiple REF CURSORs Using an OracleDataReader

This example executes a PL/SQL stored procedure that returns two REF CURSOR parameters, and reads the values using an OracleDataReader.

Filling a DataSet Using One or More REF CURSORs

This example executes a PL/SQL stored procedure that returns two REF CURSOR parameters, and fills a DataSet with the rows that are returned.

To use these examples, you may need to create the Oracle tables, and you must create a PL/SQL package and package body.

Creating the Oracle Tables

These examples use tables that are defined in the Oracle Scott/Tiger schema. The Oracle Scott/Tiger schema is included with most Oracle installations. If this schema does not exist, you can use the SQL commands file in {OracleHome}\rdbms\admin\scott.sql to create the tables and indexes used by these examples.

Creating the Oracle Package and Package Body

These examples require the following PL/SQL package and package body on your server. Create the following Oracle package on the Oracle server.

CREATE OR REPLACE PACKAGE CURSPKG AS 
    TYPE T_CURSOR IS REF CURSOR; 
    PROCEDURE OPEN_ONE_CURSOR (N_EMPNO IN NUMBER, 
                               IO_CURSOR IN OUT T_CURSOR); 
    PROCEDURE OPEN_TWO_CURSORS (EMPCURSOR OUT T_CURSOR, 
                                DEPTCURSOR OUT T_CURSOR);
END CURSPKG;
/ 

Create the following Oracle package body on the Oracle server.

CREATE OR REPLACE PACKAGE BODY CURSPKG AS
    PROCEDURE OPEN_ONE_CURSOR (N_EMPNO IN NUMBER,
                               IO_CURSOR IN OUT T_CURSOR)
    IS 
        V_CURSOR T_CURSOR; 
    BEGIN 
        IF N_EMPNO <> 0 
        THEN
             OPEN V_CURSOR FOR 
             SELECT EMP.EMPNO, EMP.ENAME, DEPT.DEPTNO, DEPT.DNAME 
                  FROM EMP, DEPT 
                  WHERE EMP.DEPTNO = DEPT.DEPTNO 
                  AND EMP.EMPNO = N_EMPNO;

        ELSE 
             OPEN V_CURSOR FOR 
             SELECT EMP.EMPNO, EMP.ENAME, DEPT.DEPTNO, DEPT.DNAME 
                  FROM EMP, DEPT 
                  WHERE EMP.DEPTNO = DEPT.DEPTNO;

        END IF;
        IO_CURSOR := V_CURSOR; 
    END OPEN_ONE_CURSOR; 

    PROCEDURE OPEN_TWO_CURSORS (EMPCURSOR OUT T_CURSOR,
                                DEPTCURSOR OUT T_CURSOR)
    IS 
        V_CURSOR1 T_CURSOR; 
        V_CURSOR2 T_CURSOR; 
    BEGIN 
        OPEN V_CURSOR1 FOR SELECT * FROM EMP;
        OPEN V_CURSOR2 FOR SELECT * FROM DEPT;
        EMPCURSOR  := V_CURSOR1; 
        DEPTCURSOR := V_CURSOR2; 
    END OPEN_TWO_CURSORS; 
END CURSPKG;
/

See Also

Other Resources

Working with Oracle REF CURSORs