NULLable Key ?

[cal]

Could someone clue me in on just what a "NULLable key" is?____If my ignorance is showing, please excuse.____Thanks.

[kfleming]

If you open up a table in exclusive mode in Visual Foxpro and look at its structure, you will see that the last column on the right is labeled Null. If a field has checkmark in this column and is used in an index, R&R will give an error message cannot use index on nullable key. The only way around to allow R&R to use an index with this field is to remove the checkmark and resave the file.____Kathleen__R&R Support

[cal]

I understand what you^ve told me. But the files I^m using are Clipper database files, using the Comix RDD, and there is not a way of checking the NULLable byte that I^ve ever heard of.____It might also be of significance that the reports in which I^m getting these errors are converted from R&R6.0 DOS, where the indexes work just fine. Thes indexes are temporary and are built at report time solely for the purpose of producing the report. It has worked well for years in 6.0.____Any further thoughts?____Thanks.____cal

[kfleming]

Do the reports still work with the DOS version?____Kathleen__R&R Support

[cal]

yes

[Randal_Ferguson_(Guest)]

Can you send me a sample table/index so I can have a look?____Kathleen__R&R Support__kfleming@livewarepub.com

[kfleming]

Yes, I will do that. Sorry for the "disappearance". I went out to do "Ride the Rockies", a week long bicycle ride, you might be able to guess where. <g>____I^ll get back to here to send this in a day or two. ____As always, thanks.____cal

[cal]

Are you still willing to take a look at this data?____I can zip the data files, cdx^s, and .rrw and the rr.udf into a single file. Have I forgotten anything?____cal

[cal]

__I^ve used Comix tables with R&R for years and have never seen any error referring to a nullable key. Is the index built using some type of user defined function or expression?____Randal

[cal]

Randall, ____Thanks for the tip. I^ll check it out in a day or two. I^ve been away for a couple of weeks.____cal