Am 14.03.21 um 18:13 schrieb Adrian Klaver:
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?
That goes in two steps:
1. The conference office will decide, which of the two rows will be
completed by the other
2. My function will do the job, but only for the columns, where it would
overwrite the default value.
By the way: the discussion here brought me to give up the completely
automated (generic) way. Now in my python code for step 2. I go through
all of the columns and decide for each of them what to do:
- either to overwrite a default value (which I define in python rather
then take it from the database)
- or put the values together (for examples in the case of "remarks",
which could be significant in both rows
- or even other handling...
Thank You all for creative thinking on my issue!
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!
--
Ulrich Goebel
Am Büchel 57, 53173 Bonn
