SQL，根据两点经纬度计算距离

SELECT 
6371 * acos(
    cos(radians(A点.latitude_f)) * cos(radians(B点.latitude_y)) * cos(
    radians(B点.longitude_y) - radians(A点.longitude_f)
    ) + sin(radians(A点.latitude_f)) * sin(radians(B点.latitude_y))
    ) as '距离/km'

from tab_name