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From:Christian Mack Date:July 17 1999 3:29pm
Subject:Re: Select on a pair of attributes
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El Jeffo wrote:
> 
> Here's an interesting philosophical question...
> 
> Say I have a table with three columns, a b and c.
> 
> a and b contain say the x and y coordinates for mass c.
> 
> I want to get the mass c for 100 (x,y) points.
> 
> Is there a better way than writing:
> 
> select from table where (a = x1 and b = y1)
>         or (a = x2 and b = y2)
>         ...
>         or (a = xn and b = yn)
> 
> I suppose I should put indexes on a and b?
> 
> Thanks for letting me borrow your brain.
> 
> Jeff

Hi Jeff

You could generate a column x_y in your table and fill it with the concatenation of x and
y.
Then make an SELECT mass FROM table WHERE x_y IN (x1y1, x2y2, ...).

Tschau
Christian

PS: Sorry for the late answer, I was on vacation.

Thread
Select on a pair of attributesEl Jeffo11 Jul
  • Re: Select on a pair of attributesChristian Mack17 Jul