Is proc sql consider a space value NULL?

[Nehcour0420]

Hi,

I am wondering if in sas proc sql, the space value (" ") is considered as a NULL value?

Thanks,

Eric

[art297]

Test it on your own system.  I think, at least on Windows, that it is unless you are using a pass thru in which case it would be cross-system dependent.

[Howles · Accepted solution]

If the evaluation is performed by the native SAS implementation of SQL, a space is considered to be null/missing, and can be compared with other values. The host OS (Windows or Unix or whatever) does not matter.

If the evaluation is done by a third-party DBMS (Oracle, MS Access, etc.),it's usually different, because comparisons involving nulls yield nulls. It should not matter whether the DBMS receives the query via pass-thru or libname engine.

Nehcour0420 wrote:

Hi,

I am wondering if in sas proc sql, the space value (" ") is considered as a NULL value?
Thanks,

Eric

[PGStats]

Windows Office Access (2007) uses a different convention when dealing with Empty and Null strings. In Access, TRUE is represented by -1.:

the functions isEmpty and isMissing, although accepted in SQL expressions, are actually VBA functions that do not return anything useful in SQL.

PG