Application Design Question

24 Apr 2007 4:06 AM

dfa_geko

Hi Everyone,

This is just a simple application design question. I was just wondering how
different people would approach this problem.

Suppose you had to design a form where you edit a record and in the form
there is a list box. You can select multiple items in the list box that are
tied to that record. (Say for example, suppose you have a record that's a
car. You can select multiple options related to the car. power locks, power
windows, automatic transmission, etc) It would be a 1 - n relationship.

In the database, you have a master record in table A. (The car) And
multiple records in another table B with a foreign key relationship. (The
options on the car)

When a user submits the form. (Or clicks a button, whatever you wish) How
would you attack this problem? Delete all the records in table B and insert
the new records. Or would you compare the values of the list box and table
B and update accordingly?

Which is the better design approach?

Thanks!

dfa_geko

24 Apr 2007 4:45 AM

David McCallum

Show quote

"dfa_geko" <nospam@nospam.com> wrote in message
news:Xns991BD6608D4DDnospamnospamcom@69.28.173.184...
> Hi Everyone,
>
> This is just a simple application design question. I was just wondering
> how
> different people would approach this problem.
>
> Suppose you had to design a form where you edit a record and in the form
> there is a list box. You can select multiple items in the list box that
> are
> tied to that record. (Say for example, suppose you have a record that's a
> car. You can select multiple options related to the car. power locks,
> power
> windows, automatic transmission, etc) It would be a 1 - n relationship.
>
> In the database, you have a master record in table A. (The car) And
> multiple records in another table B with a foreign key relationship. (The
> options on the car)
>
> When a user submits the form. (Or clicks a button, whatever you wish) How
> would you attack this problem? Delete all the records in table B and
> insert
> the new records. Or would you compare the values of the list box and table
> B and update accordingly?
>
> Which is the better design approach?
>
> Thanks!
>
> dfa_geko

We have a similar model, what we do is maintain a toBeAdded and a
toBeDeleted list. When the model is sent to the server we just iterate
through these lists.

David McCallum

24 Apr 2007 5:59 AM

RobinS

I would delete the ones there, then add the new ones. Doing a match/merge
to figure out what changed, etc., isn't worth the effort unless you're
doing your own audit trailing.

Robin S.
------------------------
Show quote

"dfa_geko" <nospam@nospam.com> wrote in message
news:Xns991BD6608D4DDnospamnospamcom@69.28.173.184...
> Hi Everyone,
>
> This is just a simple application design question. I was just wondering
> how
> different people would approach this problem.
>
> Suppose you had to design a form where you edit a record and in the form
> there is a list box. You can select multiple items in the list box that
> are
> tied to that record. (Say for example, suppose you have a record that's a
> car. You can select multiple options related to the car. power locks,
> power
> windows, automatic transmission, etc) It would be a 1 - n relationship.
>
> In the database, you have a master record in table A. (The car) And
> multiple records in another table B with a foreign key relationship. (The
> options on the car)
>
> When a user submits the form. (Or clicks a button, whatever you wish) How
> would you attack this problem? Delete all the records in table B and
> insert
> the new records. Or would you compare the values of the list box and
> table
> B and update accordingly?
>
> Which is the better design approach?
>
> Thanks!
>
> dfa_geko