Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
Any value in unique index option?
Message
De
27/08/1998 14:28:23
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Divers
Thread ID:
00130650
Message ID:
00130668
Vues:
18
Yup, use that one too. The only point I'm making is that there is still a use for it if only for the sake of us old farts who have been using it for analysis for many years :-)

>True, but SELECT DISTINCT does the same thing. And, you can easily add a COUNT() column to see how many of each value exists in the table.
>
>>Josh ---
>>
>>You are correct, however I have found Unique indexes to be invaluable when developing. A lot of my work involves redesigning databases and migrating legacy tables into VFP. When I go to normalize a column, I create a temporary compact unique IDX to see the range of values I have to be concerned with ... I just couldn't do that with a Candidate key (even if I wanted to create a CDX)
>>
>>>
>>>That's true, but a unique index is not the same as a candidate index. It doesn't keep you from adding duplicate values, it just ensures that only one record will appear in the index for each distinct key value.
>>>
>>>>Rock ---
>>>>
>>>>Yes, it's still needed. If you are creating a standalone index (IDX), Candidate is not an option.
>>>>
------------------------------------------------
John Koziol, ex-MVP, ex-MS, ex-FoxTeam. Just call me "X"
"When the going gets weird, the weird turn pro" - Hunter Thompson (Gonzo) RIP 2/19/05
Précédent
Répondre
Fil
Voir

Click here to load this message in the networking platform