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02/01/1999 14:55:23
 
 
À
02/01/1999 11:37:44
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Titre:
Divers
Thread ID:
00171828
Message ID:
00172178
Vues:
34
>Not that I am a Wunderkind, at 54 I am not a child anymore. But surrogate primary keys ARE the way to go.
>The purpose of a primary key is a UNIQUE entity to relate tables to each other.
>All you need is a unique integer to accomplish that. And never reuse primary keys. If you have a customer generated Part Number for example make it a candidate key which enforces uniqueness, too. Still add a primary key which is system generated. If the customer changes tha part number for any reason your links are still good. Otherwise you have to make sure you change the links in ALL tables where you have that part number.
>I have been using system generated keys for years starting in FP 1.0.

Peter,

Thank you. I have received many great replies to my request for information, yours among them. I can only respond that I have been using surrogate keys since dbaseII, I just did not realize they were called "surrogate" keys. In effect I was doing it before I could spell it.

Now that I know the term, I guess I'm on the same wavelink as everyone else.

regards,
Jim Edgar
Jurix Data Corporation
jmedgar@yahoo.com

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