HOWTO: Create Hierarchical Recordsets from an Oracle Stored Procedure.

• ActiveX Data Objects (ADO), versions 2.1, 2.1 SP1, 2.1 SP2, 2.5
• Microsoft Visual Basic Professional and Enterprise Editions, 32-bit only, for Windows, versions 5.0, 6.0
• Microsoft OLE DB Provider for Oracle, versions 2.0, 2.1

SUMMARY

Hierarchical recordsets in ActiveX Data Objects (ADO) give an alternative to using JOIN and GROUP BY syntax when you need to access parent-child and summary data. It is possible to create these recordsets based on recordsets created from Oracle procedures. This article gives an example of the ADO SHAPE command syntax and ADO code necessary for producing hierarchical recordsets from an Oracle Stored Procedure.

MORE INFORMATION

Sample Code

1. Run the following DDL script on your Oracle server:




      DROP TABLE Cust;

         CREATE TABLE Cust
          (CustID     NUMBER(22,6) PRIMARY KEY,
           Name   VARCHAR2(50));

         INSERT INTO Cust VALUES(100,'Sam');

         INSERT INTO Cust VALUES(222,'Kent');

         INSERT INTO Cust VALUES(333,'Sally');

      DROP TABLE Ord;
	
	 CREATE TABLE Ord
	 (ORDID     Number(22,4) Primary Key,
	  CustID    Number(22,6),
	  Total     Number(8,2));

	
	 INSERT INTO Ord VALUES(133,100,231);

         INSERT INTO Ord VALUES(123,222,899);

         INSERT INTO Ord VALUES(122,333,988);

 COMMIT;
/ 
 

2. Create the following package on your Oracle server:




       CREATE OR REPLACE PACKAGE packOrders
         AS
             TYPE tTotal is TABLE of  NUMBER(8,2)
             INDEX BY BINARY_INTEGER;
	     TYPE CCustid is TABLE of  NUMBER(22,6)
             INDEX BY BINARY_INTEGER;
             TYPE OCustid is TABLE of  NUMBER(22,6)
             INDEX BY BINARY_INTEGER;
             TYPE tname is TABLE of VARCHAR2(50)
             INDEX BY BINARY_INTEGER;
             
             	PROCEDURE GetCust
                     	(name OUT tname, Custid OUT CCUstid);
           	PROCEDURE GetOrders
                 	(Total OUT tTotal, Custid OUT OCUstid);
         END packOrders;
/ 

 

3. Create the following package body on your Oracle server:




   CREATE OR REPLACE PACKAGE BODY packOrders
         AS

         PROCEDURE GetCust
                     (name OUT tname, Custid OUT CCustid)
         IS
             CURSOR Orders_cur IS
                     SELECT Custid, Name FROM Cust;

             percount NUMBER DEFAULT 1;
	  
	  BEGIN
              FOR singleperson IN Orders_cur
              LOOP   
		      Custid(percount) := Singleperson.Custid;
                      name(percount) := singleperson.name;
                      percount := percount + 1;
              END LOOP;
          END;


         PROCEDURE GetOrders
               (Total OUT tTotal, Custid OUT OCustid)
         IS
           CURSOR person_cur IS
                      SELECT Custid, total FROM Ord;

              percount NUMBER DEFAULT 1;
	 BEGIN
             FOR singleperson IN person_cur
             LOOP
		     Custid(percount) := Singleperson.Custid;
                     Total(percount) := singleperson.total;
                     percount := percount + 1;
             END LOOP;
         END;
         END;
/ 
 

4. Open a new project in Visual Basic Enterprise edition. Form1 is created by default.



5. From the Project menu, click References, and select Microsoft ActiveX Data Objects.



6. From the Project menu, click Components, and select the Microsoft DataGrid Control 6.0.



7. Place the following controls on the form:




   Control     Name
   --------------------
   Button      Command1
   DataGrid    DataGrid1
   DataGrid    DataGrid2
 

8. Place the following code in the code module of Form1 .




Private Sub Command1_Click()

Dim cn As New ADODB.Connection
Dim rs As New ADODB.Recordset

Dim lcCOnn As String


lcCOnn = "Provider=MSDATASHAPE;Data Provider=Msdaora;Data Source=dseoracle8;User Id=demo;Password=demo"

cn.Open lcCOnn

rs.Open " SHAPE {{call packOrders.GetOrders({resultset 22, CustID, Total})}}  AS Command1 APPEND ({{call packOrders.GetCust({resultset 9, CustId, Name}) }}  AS Command2 RELATE 'Custid' TO 'Custid') AS Command2", cn

Set DataGrid1.DataSource = rs
Set DataGrid2.DataSource = rs(2).Value


End Sub

Private Sub Form_Load()
Command1.Caption = "Populate Grid"
End Sub 

9. Run the Project and click the Command1 button.


RESULT: The Grid populates with the parent and child recordsets.

REFERENCES

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:

Q174981 HOWTO: Retrieve Typical Resultsets From Oracle Stored Procedures

Q189657 HOWTO: Use the ADO SHAPE Command

Q185425 INFO ADO Hierarchical Recordsets via SHAPE APPEND w/C++/VBA/Java

Additional query words:

Keywords : kbADO kbDatabase kbOLEDB kbOracle kbGrpVBDB kbDSupport
Version : WINDOWS:2.0,2.1,2.1 SP1,2.1 SP2,2.5,5.0,6.0
Platform : WINDOWS
Issue type : kbhowto