automatic data update from SERVER to all CLIENTS connected

Hi,
i have a problem about the CLIENT-SERVER architecture procedure.
Well , i have an application in VB with ADO connection to a table in a
database on a SQLSERVER 7.0 .
Is possible to do that when a client updates a data in a field of my table ,
the SERVER communicates to all clients connected to my table that this data
are updated , without the client do anything , for example without a
client-timer to control the data in the server ?
thanksYou might want to read about "notification services" on the MS web site for this. I haven't used it
myself, but it is designed for this type of scenario.
--
Tibor Karaszi, SQL Server MVP
Archive at: http://groups.google.com/groups?oi=djq&as ugroup=microsoft.public.sqlserver
"Filippo" <rude_Fil@.yahoo.it> wrote in message news:O%uhb.24255$vO5.872426@.twister1.libero.it...
> Hi,
> i have a problem about the CLIENT-SERVER architecture procedure.
> Well , i have an application in VB with ADO connection to a table in a
> database on a SQLSERVER 7.0 .
> Is possible to do that when a client updates a data in a field of my table ,
> the SERVER communicates to all clients connected to my table that this data
> are updated , without the client do anything , for example without a
> client-timer to control the data in the server ?
> thanks
>
>

automatic data update from SERVER to all CLIENTS connected

Hi,
i have a problem about the CLIENT-SERVER architecture procedure.
Well , i have an application in VB with ADO connection to a table in a
database on a SQLSERVER 7.0 .
Is possible to do that when a client updates a data in a field of my table ,
the SERVER communicates to all clients connected to my table that this data
are updated , without the client do anything , for example without a
client-timer to control the data in the server ?
thanks"Filippo" <rude_Fil@.yahoo.it> wrote in message
news:c2vhb.26030$e6.883003@.twister2.libero.it...
> Hi,
> i have a problem about the CLIENT-SERVER architecture procedure.
> Well , i have an application in VB with ADO connection to a table in a
> database on a SQLSERVER 7.0 .
> Is possible to do that when a client updates a data in a field of my table
,
> the SERVER communicates to all clients connected to my table that this
data
> are updated , without the client do anything , for example without a
> client-timer to control the data in the server ?
> thanks
>

In theory, you could use a trigger with xp_cmdshell to call some sort of
program to notify the clients, but in practice that wouldn't be a very good
solution. It would have serious performance implications, and if the
external program failed or hung, you could block access from other clients.

A better option is probably to poll the table to see if the data has
changed, either based on a datetime column, or perhaps a 'ModifiedFlag'
column. Clients could poll directly, or use a scheduled job at regular
intervals - the job could then call your notification program, and that
would not impact the database in case of communications or other issues.

Simon|||Filippo (rude_Fil@.yahoo.it) writes:
> i have a problem about the CLIENT-SERVER architecture procedure.
> Well , i have an application in VB with ADO connection to a table in a
> database on a SQLSERVER 7.0 .
> Is possible to do that when a client updates a data in a field of my
> table , the SERVER communicates to all clients connected to my table
> that this data are updated , without the client do anything , for
> example without a client-timer to control the data in the server ?

As Simon said, there is no direct support for this in SQL Server.

For a simple solution, polling is probably best. Note here that you
could make use of a timestamp column. Such a column is automatically
updated each time you update the row, and the value is monotonically
increasing on a database-wide basis. Thus, a client can save the last
fecthed timestamp value, and then get the new one.

A more sophisticated solution would be to write an extended stored
procedure to alert the clients. As Simon pointed out, such an operation
could be detrimental to performance, if you are not careful. Best is
to alert a local process, and this process then alerts the clients
asynchronusly.

--
Erland Sommarskog, SQL Server MVP, sommar@.algonet.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techin.../2000/books.asp

automate way to build an odbc connection

is there is an automate way to build an odbc connection without usin the
windows "odbc data source administrator"?
thanks
You can programmatically create DSNs - they are just
registry entries really. Most of the examples you can find
just write to the registry. Here are a couple of samples
that should have enough information to get you going:
How To Programmatically Create a DSN for SQL Server with VB
http://support.microsoft.com/?id=184608
How to Create ODBC DSN on multiple SQL server machines
http://www.databasejournal.com/featu...le.php/2238221
-Sue
On Thu, 28 Sep 2006 15:23:24 +0200, "Sam"
<focus10@.zahav.net.il> wrote:

>is there is an automate way to build an odbc connection without usin the
>windows "odbc data source administrator"?
>thanks
>

automate way to build an odbc connection

is there is an automate way to build an odbc connection without usin the
windows "odbc data source administrator"?
thanksYou can programmatically create DSNs - they are just
registry entries really. Most of the examples you can find
just write to the registry. Here are a couple of samples
that should have enough information to get you going:
How To Programmatically Create a DSN for SQL Server with VB
http://support.microsoft.com/?id=184608
How to Create ODBC DSN on multiple SQL server machines
http://www.databasejournal.com/feat...cle.php/2238221
-Sue
On Thu, 28 Sep 2006 15:23:24 +0200, "Sam"
<focus10@.zahav.net.il> wrote:

>is there is an automate way to build an odbc connection without usin the
>windows "odbc data source administrator"?
>thanks
>

automate Access project connection to MSDE database

I'm using Visual C++ to insert records into my MSDE database. I'd like the
user to be able to view the data via Access projects. In my application, is
it possible to configure the connection settings for an Access project to
connect to the MSDE database? For example, if I were to click the View button
in my application, can I have Access project connect to the database behind
the scenes and then display the contents of the database?
Thanks!
You can use automation to launch Access and display forms and reports.
I'm not a C++ programmer, so I couldn't tell you *how* to do that.
However, I'm not sure I really understand what you are trying to do.
The phrase, "display the contents of the database" covers a lot of
ground. Perhaps you can be more specific.
--Mary
On Fri, 4 Feb 2005 15:13:02 -0800, "luv2travel"
<luv2travel@.discussions.microsoft.com> wrote:

>I'm using Visual C++ to insert records into my MSDE database. I'd like the
>user to be able to view the data via Access projects. In my application, is
>it possible to configure the connection settings for an Access project to
>connect to the MSDE database? For example, if I were to click the View button
>in my application, can I have Access project connect to the database behind
>the scenes and then display the contents of the database?
>Thanks!
|||When you create a new access project that connects to an existing database
there are certain settings that the wizard asks of you before connection to
the database can be made. How do I pass those parameters from my application
to access project? Once the project has been created after the connections
settings have been configured, the user will have full access to the tables
within the database. The user can then create queries and reports as needed.
Does this explain things a little better?
"Mary Chipman [MSFT]" wrote:

> You can use automation to launch Access and display forms and reports.
> I'm not a C++ programmer, so I couldn't tell you *how* to do that.
> However, I'm not sure I really understand what you are trying to do.
> The phrase, "display the contents of the database" covers a lot of
> ground. Perhaps you can be more specific.
> --Mary
> On Fri, 4 Feb 2005 15:13:02 -0800, "luv2travel"
> <luv2travel@.discussions.microsoft.com> wrote:
>
>
|||When you create a new access project, there are connection settings that need
to be configured before a connection can be made. How do I pass those
parameters to the connection wizard via my application? Once the connection
is made to the MSDE database, Access will then display all the tables in the
database. The user can then generate queries or reports as needed. Forms are
not necessary because if I were to create custom forms I would have created
it within my application instead of connecting to an Access database. The
reason I chose to use Access project is because I'd like the users to be able
to create queries and reports of their choosing. My job is just to dump the
data into the table and have them decide on the type of queries and reports
to generate. Is this more clear?
"Mary Chipman [MSFT]" wrote:

> You can use automation to launch Access and display forms and reports.
> I'm not a C++ programmer, so I couldn't tell you *how* to do that.
> However, I'm not sure I really understand what you are trying to do.
> The phrase, "display the contents of the database" covers a lot of
> ground. Perhaps you can be more specific.
> --Mary
> On Fri, 4 Feb 2005 15:13:02 -0800, "luv2travel"
> <luv2travel@.discussions.microsoft.com> wrote:
>
>
|||I understand now. However, your choice to use an Access project is a
bad one. Users will not be able to create and save local queries
(although they can save local reports). You would need to grant them
permissions to create views or stored procedures on the server, and
this you probably don't want to do for two reasons: (1) security and
(2) clogging the server with a lot of user objects. Unless a user is
connected as a sysadmin, they will own all their own objects and will
need to grant others permissions to use them, which you don't want to
get into. In your situation, I'd use an .mdb. You can programmatically
link tables at runtime using DAO, and if users create their own
queries, they are saved locally, not on SQL Server. HTH,
Mary
On Sun, 6 Feb 2005 23:03:08 -0800, "luv2travel"
<luv2travel@.discussions.microsoft.com> wrote:
[vbcol=seagreen]
>When you create a new access project, there are connection settings that need
>to be configured before a connection can be made. How do I pass those
>parameters to the connection wizard via my application? Once the connection
>is made to the MSDE database, Access will then display all the tables in the
>database. The user can then generate queries or reports as needed. Forms are
>not necessary because if I were to create custom forms I would have created
>it within my application instead of connecting to an Access database. The
>reason I chose to use Access project is because I'd like the users to be able
>to create queries and reports of their choosing. My job is just to dump the
>data into the table and have them decide on the type of queries and reports
>to generate. Is this more clear?
>"Mary Chipman [MSFT]" wrote: