> On 21-Jul-2004 07:45:23, Stan wrote:
> In the IBObjects group (I am posting in this group rather than IBObjects
> because my question is "wider" than just IBO issues) Helen recently wrote:
>
> "Always use a parameterised WHERE clause to limit the output to 200 rows

or

> less."
>
> This, of course, is good advice. I would like to know how to implement

this

> limitation when the result set is controlled by the user. I'm thinking of
> the (common, I suppose) case where the user types a few characters (of,

say,

> a product or a last name) and clicks a Search button, the intention being

to

> provide the user with a list they can scroll through to select their

desired

> item or person. Even if the software requires the typing of more than

just

> one or two letters before searching, it can still be the case that the
> resulting search will contain more than 200 items. What techniques or
> components might be suggested to limit the response set to 200 items while
> still allowing the user to seamlessly scroll through their intended result
> set?

I can't talk directly to the IBO style of doing this, but outside of Delphi
a technique we have adopted is to add the premise of 'Pages' to the Grid
outputs. Therefore if a user wants to retrieve, say, 10,000 rows and show
them on a grid interface, you do the query (we do this through a stored
procedure on the server so that we can control the query, start row #, end
row #, etc.) and return back a 'page' of data. We have it so that the page
size is controlled by user preference, but it works much in the same way as
a web interface.

The user can do a next/previous page, first page, last page, etc. but each
page may contain say 200 rows. This way they can walk through data, without
it requiring a huge amount of network traffic to move 10,000 rows of data
from the database to the client application.

Hope this helps.

Regards,
Myles

===============================
Myles Wakeham
Director of Engineering
Tech Solutions US, Inc.
(480) 451-7440
www.techsol.org