We just installed the latest upgrade this morning and had to uninstall
shortly thereafter in order to modify our code to account for the
correct handling of Null value comparisons.
I had read the Bug Fixes and Enhancements at the time of the install
but didn't think that the change in how R:BASE was evaluating NULL
values would affect us since we were using the OFF EQNULL setting and I
knew that we rarely compared two null values. However, a change related
to the results of comparisons of null values to text values when EQNULL
is OFF wreaked havoc with our program flow. Below I have outlined the
results of comparisons of null values to text values by R:BASE in 6.1,
6.5+ 6.5++ prerelease and 6.5++.
SET VAR v1 TEXT = NULL
SET VAR v3 TEXT = 'test value'
Version 6.5++ 6.5++ 6.5 + 6.1
Build 1.842 1.840 1.839
6.1ax
IF v1 <> v3 THEN False False True True
IF v1 NE v3 THEN False True True True
As far as I can tell, and I have done extensive evaluations with
INTEGER and DATE variables including BETWEEN and NOT BETWEEN checking,
the only change that occurred when EQNULL is set to OFF is with the
comparison of TEXT values as outlined above. Also, the reason we didn't
identify this when with the beta's is because we routinely use the NE
syntax instead of <>. Hopefully this will allow some of you out there
to plan for the upgrade better than we did.
Linda Fisher
Manager, Data Services
CIMRO Quality Healthcare Solutions
208 Metro Dr.
Jefferson City, MO 65109
