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Select records that fall 3 consecutive days within a wee
Message
De
22/12/2003 01:17:35
Hilmar Zonneveld
Independent Consultant
Cochabamba, Bolivie
 
 
À
22/12/2003 01:10:11
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Divers
Thread ID:
00861173
Message ID:
00861189
Vues:
21
>hi hilmar,
>
>actually i have more than 20 lines of code to do that, i was just hoping i could do this in few lines using select - sql.
>
>thank for you reply anyway!

In some cases, a pure-SQL solution, if it is at all possible, can be inefficient. I suspect this is one of those cases.

Actually, I am starting to think that SQL can help you reduce code (but I am still doubting about the efficiency): something like
select * from MyTable where MyDate + 1 in (select MyDate from MyTable) and MyDate + 2 in (select MyDate from MyTable)
This should give you, as a starting point, the first date in each group of three. I never tried using more than one subquery in a query, so I don't know whether this works. Otherwise, you can probably split it into two queries.

From there, you can use another SELECT with subquery, to get the second and third date.

But I suspect that the loop, which you already programmed, would be much faster.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
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