例
次の例では、IsNull
プロパティの使用方法を示します。サンプル・コードを実行する前に、必要なデータ型と表がデータベース内にあることを確認してください。「OraObjectおよびOraRefの例で使用されているスキーマ・オブジェクト」を参照してください。
Dim OraSession as OraSession Dim OraDatabase as OraDatabase Dim OraDynaset as OraDynaset Dim Address as OraObject Dim AddressClone as OraObject 'Create the OraSession Object. Set OraSession = CreateObject("OracleInProcServer.XOraSession") 'Create the OraDatabase Object by opening a connection to Oracle. Set OraDatabase = OraSession.OpenDatabase("ExampleDb", "scott/tiger", 0&) 'create a dynaset object from person_tab set OraDynaset = OraDatabase.CreateDynaset("select * from person_tab", 0&) ' insert a Null Address value instance in the table OraDynaset.AddNew OraDynaset.Fields("Name").value = "Eric" OraDynaset.Fields("Addr").Value = Null OraDynaset.update 'move to the newly added value instance OraDynaset.MoveLast 'retrieve a address column from person_tab. This Address object points to Null ' value instance set Address = OraDynaset.Fields("Addr").Value 'try to access attributes of Address. the following line will result an error msgbox Address.Street '---------ERROR------------' 'use the IsNull property to check the nullstatus If Address.IsNull = False Then MsgBox Address!Street End if