IsNull (OraObject) Property

Applies To

Description

Returns True if underlying value instance of the OraObject object is Null. Read-only at run time.

Usage

isnull = OraObject.IsNull

Data Type

Integer (Boolean)

Remarks

Accessing attributes of a Null value instance results in an error. The IsNull property can be checked before accessing attributes of an underlying value instance.

Examples

The following example shows the use of the IsNull property. Before running the sample code, make sure that you have the necessary data types and tables in the database. See "Schema Objects Used in the OraObject and OraRef Examples".

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