REF CURSOR Examples

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

Sample Description
REF CURSOR Parameters 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

Oracle REF CURSORs
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