IsNull (geometry Data Type)
The type of a geometry instance is null. Returns 0 if the instance is not null.
SQL Server type: bit
CLR type: SqlBoolean
IsNull can be used to test whether a geometry instance is null. This can produce somewhat confusing results, returning 0 if the instance is not null, but null if the instance is null.
This method is primarily used by the SQL Server infrastructure; it is not recommended that you use
IsNull to test whether an instance is null.