SELECT , ROUND( 6378.138 2 ASIN( SQRT(POW(SIN((36.666450 PI()/ 180-lat PI()/ 180 )/ 2 ),2)+ COS( 36.666450 PI()/ 180 ) COS( lat PI()/ 180 ) POW(SIN((117.076410 PI()/ 180-lng PI()/ 180)/ 2),2))) 1000) AS distance FROM agent ORDER BY distance ASC LIMIT 3