🚀 go-pugleaf

Let me first identify the situation...

I am designing a client/server application using the three-tier model.  The
project is to yield a store transaction management system.  The idea is that
upwards of 8 workstations will be placed at various locations within the
store all connected directly into the middleware server.  The workstations
will be operated by various sales people.

Here are my questions...

(1) several customers come into the store to purchase the same item
unknowing of each other's desire for the same product.  They all go to
seperate salespeople and each salesperson brings the inventory up.  Each
customer then decides to purchase the same item  The salesperson realizes
there is only one left.  So, he sets up the transaction.  However, the other
sales personnel are doing the same thing.  So, here is my question... how do
I commit the product to a sales person while he fills out pertinent
information about the customer?  How do I ensure that the item will be there
once all information is filled out and stored in the server?  If I use
transactions for this, how would I implement this measure?

(2) lets say that I have 5 salespeople employed by this store.  One sales
person is fired.  Within the database, there is a record of all sales
completed by that employee.  In creating the database, should I invoke a
relationship between the employee's id in a seperate employee's table with
that of the transaction?  Or should I just store the identity of the
employee in the transaction without any relationship established between the
two tables?  If I decide to delete the salesperson from the database and if
a relationship exists between the two tables, wouldnt that also force a
delete of all sales made by the employee?  And if it doesnt force the
deletion of transactions, then would the salesperson's ID field within the
table be left empty?

(3) When packing is necessary, should I take the middleware server offline
or can I execute a pack procedure while sales personnel have access to the
database?

(4) Lets say that I have data on my sales personnel in the same database
file as all transactions and related information.  Is there a way to lock
tables in the database from being deleted while I execute mass deletion
routines?

(5) If I choose to use Interbase/Firebird server, should I use a specific
set of database components?  Are there any advantages to using dbExpress
over ADO?


Well, I hope I havent been too cryptic.  I am theorizing how I should
proceed with a project I have been working on.  I appreciate any and all
insight... THANKS!


Steve Kothenbeutel
skothenbeutel@consultant.com