The None data source is not associated with a file. It can be used as an initial data source when you want to control when a data source associated with a dictionary is opened (by using a logic function such as setfile).

The initial behavior of the None data source is as if a file were opened with no cases. However, even after writing a case, the data source reports that it is empty. That is, loading specific cases will always fail, and writing cases will always succeed, even though the contents of the case are ignored. A None data source shares similarities with Working Storage dictionaries.

A similar data source, In-Memory, is also not associated with a data file, but cases written persist in memory until the data source is closed.

Typically CSPro uses a file extension to determine what kind of data source to open, but because there is no file associated with a None data source, you must use the connection string to specify that you want to use a None data source. The following connection string specifies a None data source:

The None data source supports the following features:

See also: Data Sources