Cory Cross wrote:
>> From: Paul McNett <[EMAIL PROTECTED]>
>> Sounds like DOW is derived from orders.date. I'd use VirtualFields for
>> this.
>> pkm ~ http://paulmcnett.com
>
> Looks like I gave a faulty analogy. Sorry to waste your time.
> The correct analogy:
> PCG: Order-LineItem-Part
No problem. VirtualFields are great for making columns with reformatting
or additional calculations of existing actual fields. You are needing
something similar: to update the values of derived fields originally
gotten via a sql join, but without executing the query all over again.
Here's what I do.
##- in my base bizobj, I have:
def afterSave(self):
self.fillDerivedFields()
def fillDerivedFields(self):
"""Hook for subclasses."""
pass
##- in my bizobjs, that have derived fields to fill upon save,
##- I create a tempcursor to get the derived values, and then
##- set the field values appropriately. Here's sample code
##- that fills in derived values from several sources:
def fillDerivedFields(self):
cur = self.getTempCursor()
# cust_name, cust_account:
cur.UserSQL = "select name, account from customers where
id='%s'" %
self.Record.cust_id
cur.requery()
if cur.RowCount > 0:
self.Record.cust_name = cur.Record.name
self.Record.cust_account = cur.Record.account
else:
self.Record.cust_name = None
self.Record.cust_account = None
# prod_name:
cur.UserSQL = """
select product_lines.name
from prod_cust
inner join product_lines
on product_lines.id = prod_cust.prod_id
where prod_cust.id='%s'""" % self.Record.prod_cust_id
cur.requery()
if cur.RowCount > 0:
self.Record.prod_name = cur.Record.name
else:
self.Record.prod_name = None
# status_name:
cur.UserSQL = "select name from production_order_status where
id=%s" %
self.Record.status_id
cur.requery()
if cur.RowCount > 0:
self.Record.status_name = cur.Record.name
else:
self.Record.status_name = None
> "description" fields change appropriately. What is the proper way to
> update them without requerying the whole Form? Or should I just
> manipulate the display boxes manually from a cursor?
I'm not sure I've come up with the best way, but it works well for me.
Paul
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