Question

Let’s say I have a Table of rows that contain coordinates.

What would be the best way to pull only the rows of coordinates which are in the radius of another coordinate?

To simplify my question, I’m giving the following example:

Table like:
Columns: Latitude, Longitude.
Row1:    23.44444  24.55555
Row2:    32.44444  28.22222
Row3:    35.11111  32.12345

In an SQL statement, how do I get the rows of coordinates that are in the radius of Row3 for example?

Answer 1

This post shows how to do this in SQL Server.

And here is how to do it in MySQL:

SELECT ((ACOS(SIN($lat * PI() / 180) * SIN(lat * PI() / 180) + 
         COS($lat * PI() / 180) * COS(lat * PI() / 180) * COS(($lon - lon) * 
         PI() / 180)) * 180 / PI()) * 60 * 1.1515) AS distance 
FROM members 
HAVING distance<='10' ORDER BY distance ASC