Represents the sole instance of the DBNull class.
Assembly: mscorlib (in mscorlib.dll)
DBNull is a singleton class, which means only this instance of this class can exist.
If a database field has missing data, you can use the DBNull object value to the field. However, most data providers do this automatically.property to explicitly assign a
To evaluate database fields to determine whether their values are DBNull, you can pass the field value to the DBNull.Value.Equals method. However, this method is rarely used because there are a number of other ways to evaluate a database field for missing data. These include the Visual Basic IsDBNull function, the Convert::IsDBNull method, the DataTableReader::IsDBNull method, the IDataRecord::IsDBNull method, and several other methods.
The following example calls the DBNull.Value.Equals method to determine whether a database field in a contacts database has a valid value. If it does, the field value is appended to the string output in a label.
Available since 10
Available since 1.1
Available since 2.0
Windows Phone Silverlight
Available since 7.0