Get all records from MySQL database that are within Google Maps .getBounds?

Question

Ok I have a database with about 1800 rows, each has a column lat and long, what I am trying to do, it query against Google Maps V3 .getBounds

Answer 1

A slightly simplified version of Vladimir's answer is working perfectly for me.

Taking an area bound by a box with a southern edge (south), a western edge (west), a northern edge (north) and an eastern edge (east). These can be derived from the Google Map .getBounds which provide south-west corner and north-east corner - you only need the two corners as these fully describe the square bounding box.

In this example our database table is called locations and contains a column for latitude and longitude.

SELECT * FROM locations WHERE
(latitude BETWEEN south AND north) AND
((west < east AND longitude BETWEEN west AND east) OR
 (west > east AND (longitude BETWEEN west AND 180 OR longitude BETWEEN -180 AND east)))

This works based on the fact that we only need to account for crossing 180/-180 longitude line as a special case - i.e. where the western longitude is a higher value than the eastern longitude. In any case where we do not cross that line the western longitude will always be less than the eastern longitude.

With regards to latitude, the southern edge will always be a lower value than the northern latitude as there is no concept of wrapping around over the poles. To cover an area over the north pole, for example we simply have all longitudes (i.e. from -180 to 180) and latitude from the southern boundary to +90.