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Pythagoras in a select statement

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audiopro

audiopro

Programmer
Apr 1, 2004
3,165
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I need to select records from a table based on a pythagorean query.
$MorcE is a fixed Easting and MorcN is a fixed Northing.
The table contains the Easting and Northing for each comparison town.
This query gives me a -2 row count (duff query) but I think it is a simple syntax problem.

Code: 
SELECT REGION, COUNTY, CITY, DISTRICT FROM JADTOWN WHERE SQRT((POWER(INT($MorcE-'EAST'),2)) + (POWER(INT($MorcN-'NORT'),2))) < 50"
NB INT has to be forced to prevent negative vars.

Also, how do I order the resulting towns in distance order?

Keith
 
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The problem is the useage of 'INT' which only refers to table column types. I need to convert each side of the equation to a positive integer as places to the west or south of the target will return a negative value.
I have checked out conv() as an alternative but cannot get this to play either.

Keith
 
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Code: 
SELECT REGION, COUNTY, CITY, DISTRICT FROM JADTOWN WHERE SQRT((POWER(242-'EAST',2)) + (POWER(463-'NORT',2))) < 50
This gives a valid query but the result of (242-'EAST') and (463-'NORT') must be forced to a positive value.

Keith
 
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Getting there:-
Moving calcs to the select side and using ABS has solved the problem but how do I order the results on the calc field?
Code: 
SELECT REGION, COUNTY, CITY, DISTRICT, EAST, NORT,SQRT((POWER(ABS($MorcE-EAST),2)) + (POWER(ABS($MorcN-NORT),2))) FROM JADTOWN

Keith
 
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keep going, you are doing incredibly well

you've answered your own problem three times in a row

keep going

:)

r937.com | rudy.ca
 
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I am still working on it, rather than allowing someone else to do my work for me but I am stumped on how to reference the calc in my query. Can I assign the calc to a var using 'select as' as I would in Foxpro, which would allow a reference to it?
Just looking for a bit of guidance.

Keith
 
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It helps to discuss a problem with colleagues but thie is difficult as I work on my own. The solution, as always, was easy once I had grasped the basics.
Code: 
SELECT REGION, COUNTY, CITY, DISTRICT, EAST, NORT,SQRT((POWER(ABS($MorcE-EAST),2)) + (POWER(ABS($MorcN-NORT),2))) as DIST FROM JADTOWN ORDER BY DIST LIMIT 50
Just a case of try it and see.

Keith
 
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