Primary Keys

  • Thread starter Thread starter js
  • Start date Start date
J

js

Hi,
I'm using Access 2002 and I have a small problem. I can't assign a
Primary Key with an index of YES (Duplicates allowed) I even tried the
Nortwinds database, If I dont touch it, it works fine but if I try to
change the settings I can't go back to having A Primary Key with Yes
Duplicates. Is this a bug or is there a flag thatI have to uncheck?
Thanks
David
 
Your suffering from a minor "conceptual misconception".

By definition the primary key must be unique, it is key, therefore you
cannot have a primary key with duplicates.

Other keys can be either unique or allow duplicates.

Access is keeping you from going there.

Cheers,

Ed Warren
 
You can't. By definition, Primary Keys must be unique. That's the definition
of a Primary Key.
 
Thanks Ed,
But why oh why in the Nortwinds database does the orders detail table
have a primary key with an index of yes (duplicats allowed) am I missing
something. Im trying to setb up my own order entry with a subform that
takes the autonumber from the main form. Thank you, Ed
David
 
In the [Order Detail] Table in NorthWind, you have a two-Field PrimaryKey.
The Fields used are OrderID and ProductID. Basically, it means that the
combination (of OrderID/ProductID) must be unique, i.e., you can cannot
order the same item twice on the same order (since you can simply increase
the quantity).

The Field OrderID *by itself* (which is what you saw) can have duplicate
values as you need to have multiple items / Records for different Product on
the same order.

Note that you can only have ONE PrimaryKey per Table. Thus if you see the
Key symbol in front of more than 1 Field, it is A multi-Field PrimaryKey,
NOT multiple Primary Keys. In the DesignView of the Table, you can open the
Indexes dialog (using the icon with the lightning symbol or the Menu View /
Indexes) and you can see all the Indexes and the PrimaryKey.
 
Thank you, I see how its set-up now. I won't be able to do that with my
database though since I'm not able to use the quantity field. So what I
basically did was set-up my order detail table without a primary field
nd set it with index yes(duplicates allowed) All the info is going to
be imported into access via notepad. Thanks.
David
 
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