Subject: | Re: CHECK and CHECKPLUS
| Date: | Fri, 6 Apr 2018 10:43:15 -0400
| From: | "Steven Green" <greens@diamondsg.com>
| Newsgroups: | pnews.paradox-dos
|
I haven't played with that in many years, but my guess is that paradox
allowing a checkplus in selected fields, as apposed to all or nothing, is
not reproducable in SQL.. probably done internally, the same way the "not"
query is done.. create a too-big answer set, then reduce it, then display it
easier to explain with the "not" query.. it grabs everything the query
requests, then does the "not" step separately.. you can can see that by
testing the size of the answer table.. it might be empty, but it'll still be
the size it was before it removed all the "not" records
--
Steven Green
Myrtle Beach, South Carolina, USA
http://www.OasisTradingPost.com
Collectibles and Memorabilia
Vintage Lego Sets and Parts
- and Paradox support, too
"Bernie van't Hof" wrote in message
news:5ac72161$1@pnews.thedbcommunity.com...
Pdox allows a query to contain both CHECK's and CHECKPLUS's which roughly
translate to SELECT DISTINCT and SELECT in sql.
sql does not allow both in the same query due to possible
uncertainties/ambiguities.
I thought I had this nailed, but on closer inspection it seems my
recollection of how pdox works in this regard is not
so clear, although I do remember sometimes struggling to get the mix right.
Anyone help?
- Bernie
|