Re: Displaying Primary Keys
Re: Displaying Primary Keys
- Subject: Re: Displaying Primary Keys
- From: Ray Ackland <email@hidden>
- Date: Sat, 27 Dec 2003 22:07:11 +1300
Drew,
public String makeSuggestion () throws probability of flame bait
{
Had the same situation as you a few months ago. Was converting a
FileMaker database where each client had a file number (really a client
id). This number was the in the field used to connect the database
tables together. It was also the number that the owners of the database
were writing on the physical folder that held all the paperwork for the
client.
Now in this situation, I look at it as though the file number (client
id) was meaningless in that it contained no data in itself. It was only
an identifier used to locate and verify the correct client. However in
this case that identifier was going to be used outside the computer
system by the people running the database, and hence needed to be
available for display.
The suggestion I received on how to do this (and chose to use) was to
add another attribute to the EOModel (I called it client number) which
mapped to the same table column as the client id. I made this attribute
read only.
The result was that WO would maintain the primary key (client id - and
yes, I know it is really CLIENT_ID) incrementing etc as necessary. It
would also display a read-only client number which the staff could use
to look up info in their files (really just a physical part of the
database).
In short, and in contrast to other suggestions, I treated the client id
to be a unique identifying piece of data used to distinguish separate
entities - but useful in the "real" world as well. It has no meaning
apart from an identifying mark, and there should never be any reason to
change it (unlike a drivers licence etc).
The only problem I have struck is that this number won't be available
on a newly created record until it is saved (and probably re-opened).
Regards,
ray.
return "hope this is useful";
}
On 27/12/2003, at 2:54, Drew Thoeni wrote:
public void newbieProblem() {
I read (and have found) that if I want to properly used object
references between enterprise objects that I must not include the
primary key in the class (i.e., I click the diamond off in EO
Modeler). However, there are times I want to display the primary key.
For example, in administration pages, I like to display the userID. Or
when editing code tables, the primary key would be useful to display.
}
public Answer newbieQuestion() {
What is the proper way to do this? Any references out there you
suggest.
}
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