Advantages of unbound forms?

[Rob Rutherford]

Access 2002 mdb front end, SQL Server 2000 back end.

I'm currently working through a chapter in Chipman and Baron's excellent book 'Microsoft Developer's Guide to SQL Server', and, if I
understand them correctly, I can make the application more scalable by using unbound forms in my Access front end instead of forms
bound to linked tables. This is supposed to save SQL Server resources by reducing the number of open connections. How exactly is the
number of connections reduced? Looking at SQL Profiler and Enterprise Manager the number of connections appears to be 2 in both of
the following cases.

Access front end with linked tables and bound forms
-----------------------------------------------------
If I open any number of linked tables, only 2 connections to SQL Server seem to be opened.


Access front end with no linked tables or unbound forms
---------------------------------------------------------
If I use one global ADO connection plus pass-through queries this again gives a total of two connections because the pass-through
queries all seem to use the same connection.


If someone can put me straight I'd appreciate it.

 

[Guest]

I have gone this route and its a lot of work so be aware.
Expect development time ti increase exponentially.
You have total control but also total responsibilty for all table
input/output.
Effectively almost all Access built-in facilities are shut off when you use
unbound forms. All column attributes (as defined in your tables) are unknown
to Access so you have to check every column for length for example. You will
also have to check for conflicting updates yourself, by re-reading before
writing to make sure no intervening updates have been made.
There are various techniques for minimizing the number of connections. The
most important thing though is to ask for only the data you need and no more.
Avoid SELECT * for example.

 

[Rob Rutherford]

Thank you.

I have gone this route and its a lot of work so be aware.
Expect development time ti increase exponentially.
You have total control but also total responsibilty for all table
input/output.
Effectively almost all Access built-in facilities are shut off when you use
unbound forms. All column attributes (as defined in your tables) are unknown
to Access so you have to check every column for length for example. You will
also have to check for conflicting updates yourself, by re-reading before
writing to make sure no intervening updates have been made.
There are various techniques for minimizing the number of connections. The
most important thing though is to ask for only the data you need and no more.
Avoid SELECT * for example.