How to Retrieve Data Points Within Overlapping Marker Radii from a Geospatial Database?

Retrieve Results Within Overlapping Marker Radii from Database

The objective is to retrieve data points that fall within the overlapping radii of multiple markers in a geospatial database. To achieve this, you must employ the equation of a circle to determine whether a point lies within a given radius.

Considering User B's location as the circle's center and User A's location as points on the circle's perimeter, the equation of the circle, converted to kilometers for consistency, transforms into:

((x-x1)*111.12)^2 + ((y-y1)*111.12)^2 = 4      (=2^2)

where:

• x and y represent the latitude and longitude of User A's location
• x1 and y1 represent the latitude and longitude of User B's location
• 111.12 converts degrees of latitude and longitude to kilometers

Translating this equation into SQL yields:

SELECT A.user_id, A.radius_id, A.latitude, A.logitude
FROM UserA AS A, 
     (SELECT user_id, latitude, longitude 
       FROM UserB 
       WHERE user_id = 8) AS B
WHERE (POW((A.latitude-B.latitude)*111.12, 2) + POW((A.longitude - B.longitude)*111.12, 2)) <= 4

Note: For enhanced accuracy, consider using (A.longitude - B.longitude)*111.12*cos(A.latitude) or (A.longitude - B.longitude)*111.12*cos(B.latitude) instead of (A.longitude - B.longitude)*111.12 in the equation.

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