Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > Python > Re: Foxpro goto command and deleted records

Reply
Thread Tools

Re: Foxpro goto command and deleted records

 
 
Ethan Furman
Guest
Posts: n/a
 
      07-18-2012
MRAB wrote:
> On 18/07/2012 03:19, Ethan Furman wrote:
>> MRAB wrote:
>>> On 17/07/2012 23:57, Ethan Furman wrote:
>>>> In Foxpro if you do a
>>>>
>>>> GOTO 7
>>>>
>>>> with deleted off and record 7 is deleted, the record pointer doesn't
>>>> move (at least in version 6).
>>>>
>>>> I don't like that.
>>>>
>>>> I see four other options:
>>>>
>>>> 0) don't move the pointer (listed for completeness)
>>>> 1) go to that record anyway
>>>> 2) go to the next undeleted record
>>>> 3) go to the seventh undeleted record (possibly the least practical)
>>>> 4) raise an exception
>>>>
>>>> Any opinions?
>>>>
>>> What happens when you 'delete' a record? Does it disappear immediately,
>>> or is it merely marked for deletion?

>>
>> Marked for deletion.
>>
>>> If it is marked for deletion, can it be unmarked? Will a marked record
>>> be removed when the file is closed, or does the file need to be
>>> explicitly purged/compacted?

>>
>> Yes, it can be unmarked. No, the table must be explicitly packed.
>>
>>> If it is merely marked, then I think the best option is 1, or possibly
>>> 4 if the file is compacted when closed.

>>
>> There is a use_deleted setting that controls whether deleted records are
>> accessed or skipped. Skipping is fine when looping, not so fine when
>> going directly to a particular record.
>>

> If use_deleted is false, does that mean that deleted records are
> hidden, or just that when iterating through the records the deleted
> ones aren't yielded?


Definitely the latter, but I'm starting to wonder if the former should
also be the case.

~Ethan~
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Foxpro goto command and deleted records Ethan Furman Python 3 07-18-2012 04:26 PM
Re: Foxpro goto command and deleted records Ethan Furman Python 0 07-18-2012 02:19 AM
Re: Foxpro goto command and deleted records Ethan Furman Python 0 07-18-2012 02:16 AM
Re: Foxpro goto command and deleted records MRAB Python 0 07-18-2012 12:01 AM
Re: Foxpro goto command and deleted records Ian Kelly Python 0 07-17-2012 11:50 PM



Advertisments