postgresql 计算两点距离的2种方法小结

postgresql计算两点距离

下面两种方法：

select 
st_distance(
 st_setsrid(st_makepoint(115.97166453999147,28.716493914230423),4326)::geography,
 st_setsrid(st_makepoint(106.00231199774656,29.719258550486572),4326)::geography
),
st_length(
 st_makeline(
 st_makepoint(115.97166453999147,28.716493914230423),
 st_makepoint(106.00231199774656,29.719258550486572)
 )::geography
)

备注：

st_geomfromtext('linestring(115.97166453999147 28.716493914230423,106.00231199774656 29.719258550486572)')与
st_makeline(
	st_makepoint(115.97166453999147,28.716493914230423),
	st_makepoint(106.00231199774656,29.719258550486572)
)等价
 
st_geomfromtext('point(115.97166453999147 28.716493914230423)',4326)与
st_setsrid(st_makepoint(115.97166453999147,28.716493914230423),4326)等价
 
st_setsrid(st_makepoint(115.97166453999147,28.716493914230423),4326)::geography与
geography(st_setsrid(st_makepoint(115.97166453999147,28.716493914230423),4326))、
st_geographyfromtext('srid=4326;point(115.97166453999147 28.716493914230423)')等价
(::geography是postgis中的转换类型语法,把geometry转成geography)

补充：postgresql计算两点欧式距离（经纬度地理位置）

我就废话不多说了，大家还是直接看代码吧~

create or replace function getdistance
( 
 lon1 numeric,
 lat1 numeric, 
 lon2 numeric, 
 lat2 numeric 
) 
returns int 
as 
$body$ 
declare 
v_distance numeric;
v_earth_radius numeric;
radlat1 numeric;
radlat2 numeric;
v_radlatdiff numeric;
v_radlngdiff numeric;
begin 
 --地球半径
 v_earth_radius:=6378137;
  
 radlat1 := lat1 * pi()/180.0;
 radlat2 := lat2 * pi()/180.0;
 v_radlatdiff := radlat1 - radlat2;
 v_radlngdiff := lon1 * pi()/180.0 - lon2 * pi()/180.0; 
 v_distance := 2 * asin(sqrt(power(sin(v_radlatdiff / 2), 2) + cos(radlat1) * cos(radlat2) * power(sin(v_radlngdiff/2),2)));
 v_distance := round(v_distance * v_earth_radius);
 return v_distance; 
end;
$body$
language 'plpgsql' volatile;

create or replace function getdistance
( 
 i_lngbegin real,
 i_latbegin real, 
 i_lngend real, 
 i_latend real 
) 
returns float 
as 
$body$
/*
 * 
 * select getdistance_bygispoint(116.281524,39.957202,117.648673,38.42584) as distance;
 * */ 
declare 
v_distance real;
v_earth_radius real;
v_radlatbegin real;
v_radlatend real;
v_radlatdiff real;
v_radlngdiff real;
begin 
 --地球半径
 v_earth_radius:=6378.137;
  
 v_radlatbegin := i_latbegin * pi()/180.0;
 v_radlatend := i_latend * pi()/180.0;
 v_radlatdiff := v_radlatbegin - v_radlatend;
 v_radlngdiff := i_lngbegin * pi()/180.0 - i_lngend * pi()/180.0; 
 v_distance := 2 * asin(sqrt(power(sin(v_radlatdiff / 2), 2) + cos(v_radlatbegin) * cos(v_radlatend) * power(sin(v_radlngdiff/2),2)));
 v_distance := v_distance * v_earth_radius*1000; 
 return v_distance; 
end;
$body$ 
language 'plpgsql' volatile;

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。如有错误或未考虑完全的地方，望不吝赐教。