When do I use TADOTable, TADOQuery,TADODataSet ?

Thomas Richter

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Apr 25, 2000, 3:00:00 AM4/25/00

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Hi folks,

a simple question for you but not for me:

- when do I use a TADOTable and when a TADOQuery ?
- and also why should I use a TADODataSet when I can access all my fields
from TADOQuery ?

Thank you
Thomas

Brandon Lilly

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Apr 25, 2000, 3:00:00 AM4/25/00

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My first answer would be "TADOQuery et al does not give you access the
commandtimeout property, which has really bitten us in the butt countless
times. We finally converted everything to either TADOCommand or TADODataset
to give us greater flexibility, I haven't really missed the other
controls."

Brandon Lilly
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Remove "no_spam" from address to email directly

"Thomas Richter" <thomas_r...@hotmail.com> wrote in message
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Xavier Pacheco (TeamB)

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Apr 25, 2000, 3:00:00 AM4/25/00

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Thomas,
These follow the same paradigm as the TTable vs TQuery. You'd use a
TTable if accessing local data such as Access, Foxpro, etc. You'd use
a TADOQuey when accessing SQL based RDBMS. I can't speak for ADO but
as for the TTable vs TQuery, there are performance issues depending on
which you use, that is, you should stick to TQuery when hitting SQL
databases. I'm assuming the same is true with ADO.

-- x

Xavier Pacheco (TeamB)
Xapware Technologies Inc.
www.xapware.com
www.xapware.tzo.com

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Harry Van Tassell

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Apr 25, 2000, 3:00:00 AM4/25/00

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"Thomas Richter" <thomas_r...@hotmail.com> wrote in message
news:8e40ko$t...@bornews.borland.com...
> Hi folks,
>
> a simple question for you but not for me:
>
> - when do I use a TADOTable and when a TADOQuery ?
> - and also why should I use a TADODataSet when I can access all my fields
> from TADOQuery ?
>
> Thank you
> Thomas
>

Thomas,

A simple question with no simple answer.;>)

While those just starting ADO may find it somewhat daunting to learn all
it's complexity, the ADODataSet component should be used and there is
actually no need for either a TADOTable or a TADOQuery component. . They
surface only a portion of the functionality of TADODataSet from which they
descend. These were included in ADOExpress as compatibility components to
ease the task of quick and dirty migrations of old BDE apps to ADO.

Many new users, especially those moving from classic file based backgrounds,
have been disappointed with the performance of ADO and this usually is the
result of a their first test using the TADOTable component to display a
large table in a grid.

--Hairy

Arnold Johnson

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Apr 26, 2000, 3:00:00 AM4/26/00

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Hello Harry,
I sent an you email a while back for assistance on dealing with
OnFetchProgress and OnFetchComplete. I am trying to do something similar
like you have in ADOExplorer whereby a query's progress can be displayed
and cancelled if so desired. I need to know the setting to use for a
TADOQuery or TADODataSet (as you have mentioned below).
Can you help?
Thanks in advance.
In article <8e4cot$4p...@bornews.borland.com>, Harry Van Tassell
<ha...@nada.com> writes

--
Arnold Johnson

Bill Seven

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May 11, 2000, 3:00:00 AM5/11/00

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Hi Hairy,

If you substitute TADODataSet for TADOTable, how do you get a master-slave,
er, detail thing going? In my TADODataSet, all I've got is the MasterFields
property, no MasterSource. The TADOTable has masterSource as a property,
which makes it oh so easy to create the master-slave relationship. (Of
course yes it is awful slow with the table).

Bill

Harry Van Tassell <ha...@nada.com> wrote in message
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Colin Acheson

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May 12, 2000, 3:00:00 AM5/12/00

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That had me struggling for a while too. Just connect a standard
TDataSource to the master TADODataSet and specify it as the
MasterSource.

Regards,
Colin Acheson

On Thu, 11 May 2000 17:16:12 -0400, "Bill Seven" <bi...@include.com>
wrote:

Colin Acheson

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May 12, 2000, 3:00:00 AM5/12/00

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Correction:
I meant connect a standard TDataSource to the master TADODataSet and
specify it as the "DataSource" property of the detail TADODataset.

Regards,
Colin Acheson

Harry Van Tassell

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May 12, 2000, 3:00:00 AM5/12/00

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> If you substitute TADODataSet for TADOTable, how do you get a
master-slave,
> er, detail thing going? In my TADODataSet, all I've got is the
MasterFields
> property, no MasterSource. The TADOTable has masterSource as a property,
> which makes it oh so easy to create the master-slave relationship. (Of
> course yes it is awful slow with the table).
>

Hi bill 7,

If you prefer using the TTable approach there is no reason to change and yes
it gets slower and slower as you scale upward. You might as well begin the
paradigm shift from xBase to C/S and start using querys.

--Hairy