Very Computer

I'm using Delphi at work to write a phone message recorder:
multiple users (up to six at a time) would have it running minimized,
and when they take a phone call they use it to type in and recall details
-- who called, when, what they were calling about, and so on.

The details of all our customers are stored in one database table,
the details of all the recent messages are stored in another.
But there doesn't seem to be a way for one instance of the program
to notify all other instances on other computers at the same time,
if either database changes.
I have a "table of contents" displaying both databases on the form,
and I want that table of contents to update automagically whenever a
customer or message is inserted, deleted or edited.

How do I do this?  It's driving me batty!

: Paul Sleigh :
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I can face anything, except the future,  |  Eric the Fruitbat, aka Paul Sleigh
and certain parts of the past            |  In the SCA: Eric of Tobar Mhuire

Quote:>The details of all our customers are stored in one database table, the
details  
>of all the recent messages are stored in another. But there doesn't seem
to be  
>a way for one instance of the program to notify all other instances on
other  
>computers at the same time, if either database changes.
>I have a "table of contents" displaying both databases on the form, and I
want  
>that table of contents to update automagically whenever a customer or
message  
>is inserted, deleted or edited.

Quote:>How do I do this?  It's driving me batty!

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"For off-shore pricing on Printing, Data entry, CAD conversion,
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Quote:

>Have you tried attaching the TTable's refresh method to a TTime's ontimer
>event?

Todd
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"His mind is somewhat too much taken up with his mind." - John Earle
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My problem was this:
User A and User B are both using a program.
The program accesses some tables and displays them in various ways,
including an OwnerDraw TListBox
listing the first half dozen fields of each of one table's records.

If User A makes a change to a table,
and User B presses some sort of "Reread" button,
then User B's instance of the fields and contents will be up to date.
However, having a Reread button seemed silly to me.

What I've done is this:
I created a table called "UPDATE.DB", with three fields:
TableName, a string;
Date, a long integer; and
Time, a long integer.

Using the Database Desktop,
I set up a record in this table for each other table I'm using.
It looked something like this:
['APPLE-TABLE',0,0]
['BAT-TABLE',0,0]
['CAMEL-TABLE',0,0]
etc etc etc

I then created an object that contains a reference to such a table,
plus a LongInt each for Date and Time.

Now, whenever User A or B accesses the table of contents,
the object I defined checks in the relevant row of the Update table,
and checks to see if its own Date and Time match the ones stored there.
If they don't, the "Modified" property of that object returns True,
and incidentally sets Date and Time to the values stored there.

Also, to the OnAfterPost method of the various tables (Apple, Bat, Camel,
etc) I added a call to that same object's Modify procedure,
which simply stores the current date and time, as long integers,
in the relevant rows of the update table.

I can connect this to a timer too,
as someone suggested,
to make it check the update table every second or so.

Since it only updates when it has to,
it seems like as close as I can get to an ideal method.
I do wish I could access the table's DOS access-time-and-date stamp,
but failing that this seems to be the best way.

Thanks to all of you for your suggestions.

: Eric :
--
------------------------------------------------------------------------------
I can face anything, except the future,  |  Eric the Fruitbat, aka Paul Sleigh
and certain parts of the past            |  In the SCA: Eric of Tobar Mhuire