Question about libraries.

[jaliu]

I'm kind of confused about what a library is. I think it's just a folder that contains folders and files, but this is not clear to me. If a library doesn't have any files (but rather has files in subfolders), will files not be accessible? Would we/can therefore add another libref to a subfolder to access those files within subfolders?

[PaigeMiller]

Whatever folder(s) the LIBNAME statement mentions must contain the SAS data set files. SAS doesn't look in subfolders, unless you specifically state the subfolder in the LIBNAME statement.

Would we/can therefore add another libref to a subfolder to access those files within subfolders?

Other way around ... add a subfolder to the LIBNAME statement.

[Kurt_Bremser]

A library in SAS is a reference to a location that contains SAS files like datasets, views or catalogs.

On UNIX systems and Windows that location is a directory.

Libraries cannot be nested (a library cannot contain another library, all libraries exist on the same level side by side).

It is possible to create a directory as a subdirectory of another, and assign library references to both, but when viewing from inside SAS, that hierarchy will not be represented.

[Panagiotis]

SAS libraries access data. You set a library to some location (folder, database, Excel workbook). You can then references that library name when working with the data in those locations.

You can also check out the free SAS Programming course. Go to Lesson 2, then Accessing Data Through Libraries. Practices doing that with the Excel file, and folder paths.

[ThdB]

It is possible to use multiple folders in one library 

libname income ('corpsale','retail');

However, if a dataset is stored in both folders with the same name, sas uses the dataset from the first folder.