dBase III - indexing on date 2

[turvillevalley]

My dBase Bible tells me that if I index on date (MM/DD/YY)I'll end up with a list sorted by Month, first.
It then says I should ...
index on $(Date,7,2)
... which translates as "Index on the last two characters in the date starting with the 7th character"

The trouble is I get told this is a syntax error!
I have tried all the permutations I can think of to no avail - does anybody have any Idea how I can acheive a 'proper' Date Index, please?

Regards,

Chris

 

[tviman]

To the best of my knowledge, you'll have to turn your date into a character string to do this. Try indexing on DTOC(<your date>) and you should be alright.

There's always a better way. The fun is trying to find it!

 

[turvillevalley]

Thanks TVIMAN,

Being impatient I actually ended up using DTOC as a work around, a pretty tedious one, but it seems to have worked.
That said, it's nice to know that my train of thought was on a similar track to somebody else.

Thanks for your help.

Best regards,

Chris

 

[dbMark]

Wow, dBase 3 goes way back in time. Does it have the DTOS() function? It will return the date as an 8-character string such as "20050425", the perfect arrangement for most indexes.

If using DTOC() then this longer code does the same, assuming your display format is mm/dd/ccyy:

* myDate is a date field
SET CENTURY ON
INDEX ON RIGHT(DTOC(myDate),4)+LEFT(DTOC(myDate),2)+SUBSTR(DTOC(myDate),4,2) TAG DateOrder

Just remember not to reindex and accidently change the index logic by having CENTURY set off when it should be on, or the index will display a skewed order! Of course if you keep the century off all the time, then this will work:

INDEX ON RIGHT(DTOC(myDate),4)+LEFT(DTOC(myDate),2)+SUBSTR(DTOC(myDate),4,2) TAG DateOrder

dbMark

 

[turvillevalley]

Thanks dbMark - Your are correct, db III goes Way back, 1985, at least!

Unfortunately there's no Century to set!
Also it only has DTOC, not DTOS.
So, it looks like the work-around which TVIMAN suggested is the best bet. In fact, the work around works well, luckily for me.


All the best,

Chris