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Any value in unique index option?
Message
De
27/08/1998 14:31:50
 
 
À
27/08/1998 14:29:55
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Divers
Thread ID:
00130650
Message ID:
00130673
Vues:
17
It was my personal statement :), i.e. I will never use it. Would you like your users to call me :)?

>Yeah, I could. And you are right, *never* in an application...but the minute I write something definitive like "never use a unique IDX in an application" a user will call me and I'll need to use one :)
>
>
>>Could you just SELECT DISTINCT ... ? Basically, there is nothing against using these indexes for ad-hoc operations, but seeing them in application, it's not good
>>
>>>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.
>>>>>
Edward Pikman
Independent Consultant
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