Re: ADODataSet browsing

Article View: borland.public.cppbuilder.database.ado

Article #2535

Back to borland.public.cppbuilder.database.ado Previous Next

#2535

From: Jerry Bloomfield (TeamB)
Date: Mon, 19 May 2003 20:29

30 lines
2210 bytes

On Tue, 20 May 2003 03:01:12 +0800, "booker" <diablohsh@163.net> wrote:

>Dataset->Close();
>Dataset->CommandText="select column1,column2 from tbl_some";
>Dataset->Open();
>
>Dataset->First();
>for(int i=0;i<Dataset->RecordCount;i++)
>{
>    ShowMessage(Dataset->FieldByName("column1")->AsString);
>    ShowMessage(Dataset->FieldByName("column2")->AsIntegger);
>    Dataset->Next();
>}
>
>got that?

But,  using RecordCount can be "expensive" if you are dealing with a large
number of rows.  It may be more efficient to loop "while ( !Dataset->Eof ).

Using RecordCount will force some database interfaces to retrieve all rows
into local [most likely virtual] storage,  and count them.  Doing this will
make it much faster to access each row,  but it will cause your table open
times to take minutes to hours depending upon the amount of data
involved...

Jerry Bloomfield (TeamB)
-- 
http://www.teamb.com                                      JersWork@iwc.net
Please do *NOT* send private e-mail without prior permission (my anti-spam 
filters will probably just delete it anyway <g>)

Technical Details

Message-ID: <jdficvs9er21uthamhn31svh1g7jmc0lgb@4ax.com>

Path:

arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-03!sn-xit-01!sn-xit-08!sn-xit-09!supernews.com!newsfeed.wirehub.nl!news.kweb.on.ca!KWeb!newsgroups.borland.com!not-for-mail

References: <3ec77698@newsgroups.borland.com> <3ec929f0$1@newsgroups.borland.com>

Show Full Headers

Complete Article Headers

X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 10698b,39ca1f942131ec29
X-Google-Attributes: gid10698b,public
X-Google-ArrivalTime: 2003-05-19 13:32:25 PST
From: "Jerry Bloomfield (TeamB)" <JersWork@iwc.net>
Newsgroups: borland.public.cppbuilder.database.ado
Subject: Re: ADODataSet browsing
Date: Mon, 19 May 2003 15:29:54 -0500
Organization: LSVFA - Latest Software Version Freaks Anonomous
Reply-To: "Jerry Bloomfield (TeamB)" <JersWork@iwc.net>
Message-ID: <jdficvs9er21uthamhn31svh1g7jmc0lgb@4ax.com>
References: <3ec77698@newsgroups.borland.com> <3ec929f0$1@newsgroups.borland.com>
X-Newsreader: Forte Agent 1.92/32.572
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
NNTP-Posting-Host: 216.142.220.8
X-Trace: newsgroups.borland.com 1053376170 216.142.220.8 (19 May 2003 13:29:30 -0700)
Lines: 30
X-Authenticated-User: jerswork
Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-03!sn-xit-01!sn-xit-08!sn-xit-09!supernews.com!newsfeed.wirehub.nl!news.kweb.on.ca!KWeb!newsgroups.borland.com!not-for-mail

Reply to Parent Message