Here is the trick to find the radius distance in miles directly from the latitude & longitude data store in your mysql table. This is a very helpful trick which i use while creating webservices for mobile apps.

```
SELECT
id, (
3959 * acos (
cos ( radians(78.3232) )
* cos( radians( lat ) )
* cos( radians( lng ) - radians(65.3234) )
+ sin ( radians(78.3232) )
* sin( radians( lat ) )
)
) AS distance
FROM markers
HAVING distance < 30
ORDER BY distance
LIMIT 0 , 20;
```

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