System.DBNull
represents a non-existing value. DBNull
is a singleton. DBNull
and null
are not the same thing. System.DBNull
is equivalent to System.Convert.DBNull
, as can be demonstrated with the following PowerShell statement: [System.Convert]::DBNull.Equals([System.DBNull]::Value)
IsDBNull
method of the Microsoft.VisualBasic.Information
class. System.Management.Automation.Language.NullString
and System.Reflection.Missing
, and the VBA null
value.