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SELECT * FROM postcodelatlng  WHERE ( 3958 * 3.1415926 * sqrt( (latitude - '.$lat.') * (latitude - '.$lat.') + cos(latitude/57.29578) * cos('.$lat.'/57.29578) * (longitude-'.$lon.') * (longitude-'.$lon.') ) / 180 ) <= '.$radius.';'


this query is working perfectly fine .but i dont get the formula .how is it working . can anyone kindly explain this formula or can share any reference link where i find this . (Note : this question is asked after investing alot of time to find the explanation of this formula ).

What I have tried:

formula is working perfectly fine . but needs explanation
Posted
Updated 26-May-22 0:07am

1 solution

Quote:
this query is working perfectly fine .but i dont get the formula .how is it working .

For distance between 2 point on earth, the answer is 'great circle formula'
Great circle - Wikipedia[^]
Great-circle distance - Wikipedia[^]
   

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