Re: Business objects, subset of collection

I don't think you should have a grid showing all invoices for one
vendor. It is not practical in the GUI.

The invoices shown are for the selected vendor AND day.

Fine. If the set of invoices in the grid are limited, it wouldn't take
very long time to reposition the cursor.

But how long does it take to execute the SQL query? Without the
metrics, it is impossible to tell if the solution works or not.

Vendor grid: Contains various levels of summary info for ALL invoices
and scheduled payments for each vendor.

I doubt that

select vendorid, sum(amount)
from invoice
group by vendorid

would take too long time. And if it do, you should use materialized
views. If your database doesn't support that, the last resort would be
to create a new redundant column in the vendor table, containing the
sum of all invoice amounts. Obviously this would introduce integrity
problems, and should only be considered if absolutely necessary.

What about payments made from other client computers? Are they
reflected instantly too?

Payments are only scheduled by one person.  In a multi-user
application, there would obviously have to be some persistance to a
shared medium (RDB or similar).

If you are building a single-user application, it is easier to live
without a database.

When you say "persistance", are you talking about writing to disk?
Calling
insert into payment (invoiceid, date, amount) values ...

has very little to do with persistence. If, when or how the database
writes something to disk, is controlled by the database.

//frebe
.

Relevant Pages

  • Re: Business objects, subset of collection
    ... The application is for scheduling of payments of invoices and ... for the selected vendor ... subsets of the vendors / invoices: ... I have a Setfilter(DateTime filterDate) methods defined in the ...
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  • Re: Keeping "Header Item" and Total on the Same Line?
    ... One possible way is to include Vendor Name and Total of Invoices in the group header. ... totals and vendors, and shows the total for each vendor ...
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  • Re: Business objects, subset of collection
    ... The invoices shown are for the selected vendor AND day. ... Vendor grid: Contains various levels of summary info for ALL invoices ... and scheduled payments for each vendor. ...
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  • Re: My first enjoyable Darjeeling
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  • Re: Poly Couples
    ... If you want to claim that OO is the consolution prize for lame database ... there is a metamodel which describes the hierarchy. ... Metamodel is stored in SQL, however, the data is stored in non ... vendor, and the structure is different than the one you use originally. ...
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