On 3/14/21 6:30 AM, Ulrich Goebel wrote:
Hi,
Am 13.03.21 um 22:21 schrieb Tim Cross:
I think you may need to re-think your design or at least come at it from
a different perspective. As shown by another post in the thread, at some
level, this is 'sort of' possible, but it will be ugly and fragile.
Yes, I am re-thinking allredy...
o.k.: For a conference I have a tbl_person which holds all peoble which
are involved: participants and people which provide private lodgins for
other participants. (There are much more roles, but for illustration
these two should be enough.) Of course each person can have one or more
roles at the conference, a n-n-relation models that. Now our workflow
allows that one person find it way in the tbl_person twice (ore even
more often): for example the conference office generates a row for Tom,
because he provides private lodgin. Later on Tom decides to participate
an fills the online registration formular. These data generate the
second row for Tom. Both rows hold significant information which the
other doesn't hold. Let's say the online register gave the birthday, the
other holds information about the lodgin (bed with or without
breakfast). The next step then is that the conference office get notice
of the doubled person an should make one row out of the existing two
rows. The office decide which of the two rows should be completed with
data from the other row. Therefore I would like to pick the columns in
the first row where we have default values and replace it by the value
from the second row.
This is just part of a bigger issue, which value to believe:
col_1 col_2 col_3 col_4
row 1 default some_val default some_val
row 2 other_val default default other_val
How do you arrive at assumption that row 2(or any other row) has
precedence over row 1?
There are more ways to end with two or even more rows per person. May be
it would have been much better to avoid these possibilities. But for the
moment I have a given database structure running in productive mode, so
it is not easy to re-structure the structure or even the workflows...
Thanks for patience reading all that!
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
