Using OO4O Automation with Visual Basic

When accessing the Oracle Object Server using the OLE Automation interface and Visual Basic, you must create each object explicitly, except for the client object, which is always created automatically. The following code fragment demonstrates how to create first all of the objects required by a dynaset and then the dynaset itself.

  1. Start Visual Basic and create a new project then add the following code to the Declarations section of a form.

...

' Declare variables

Dim OraSession As OraSession

Dim OraDatabase As OraDatabase

Dim OraDynaset As OraDynaset

Dim OraFields As OraFields

2. Add the following code to the Load procedure associated with the form to access the display the Oracle data.

' Create the OraSession Object. Notice that this is the

' only object created via the CreateObject method. The

' argument to CreateObject is the name by which the

' OraSession object is known to the OLE system.

Set OraSession = CreateObject("OracleInProcServer.XOraSession")

' Create the OraDatabase Object by opening a

' connection to Oracle.

Set OraExampleDB = OraSession.OpenDatabase("ExampleDb",

"scott/tiger", 0&)

' Create the OraDynaset Object; name it EmpTable.

Set EmpTable = OraExampleDB.CreateDynaset("select * from emp", 0&)

' You can now display or manipulate the data in the

' dynaset named EmpTable. For example:

Set EmpFields = EmpTable.fields

EmpTable.movefirst

Do While Not EmpTable.EOF

MsgBox EmpFields("ename").Value

EmpTable.movenext

Loop

3. Run the form to view the results.

See Quick Tour with Visual Basic for more information on using OO4O with Visual Basic.

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