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Index on DATETIME() fields
Message
De
02/12/2008 09:54:25
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Divers
Thread ID:
01364954
Message ID:
01365115
Vues:
13
>>I have two fields that are DateTime(). What is the best way to index them? I have tried:
>>
>>INDEX ON TRANSFORM(Field01) + TRANSFORM(Field02) ASCENDING TAG Temp
>>
>>But they don't seem to order correctly. I would also like the index to be as efficient as possible.
>
>Jay, I use dtos(datefield), because it puts it in order by year/month/date. The dtoc() gets it into a string but the order may be a little strange because the year is last.

DTOC() is actually dependent on the current SET DATE setting, so it's a very risky choice for indexes. For a date field, as you say, DTOS() is the way to go. For datetime, as others said, TTOC(,1).

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