最新国产好看的视频,伊人天堂AV在线,国产Aaaaaa视频,蜜臀视频在线观看一区,人妻av色图,密臀久久久精品影片,青青视频免费观看毛片,久草在线观看视,国产三级精品色情在线

postgresql 計算兩點距離的2種方法小結(jié)

 更新時間:2021年01月26日 10:25:50   作者:溫水煮螞蟻  
這篇文章主要介紹了postgresql 計算兩點距離的2種方法小結(jié),具有很好的參考價值,希望對大家有所幫助。一起跟隨小編過來看看吧

postgresql計算兩點距離

下面兩種方法:

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
)

備注:

ST_GeomFromText('LINESTRING(115.97166453999147 28.716493914230423,106.00231199774656 29.719258550486572)')與
ST_MakeLine(
	ST_MakePoint(115.97166453999147,28.716493914230423),
	ST_MakePoint(106.00231199774656,29.719258550486572)
)等價
 
ST_GeomFromText('POINT(115.97166453999147 28.716493914230423)',4326)與
ST_SetSRID(ST_MakePoint(115.97166453999147,28.716493914230423),4326)等價
 
ST_SetSRID(ST_MakePoint(115.97166453999147,28.716493914230423),4326)::geography與
Geography(ST_SetSRID(ST_MakePoint(115.97166453999147,28.716493914230423),4326))、
ST_GeographyFromText('SRID=4326;POINT(115.97166453999147 28.716493914230423)')等價
(::geography是postgis中的轉(zhuǎn)換類型語法,把geometry轉(zhuǎn)成geography)

補充:postgresql計算兩點歐式距離(經(jīng)緯度地理位置)

我就廢話不多說了,大家還是直接看代碼吧~

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 
 --地球半徑
 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 
 --地球半徑
 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;

以上為個人經(jīng)驗,希望能給大家一個參考,也希望大家多多支持腳本之家。如有錯誤或未考慮完全的地方,望不吝賜教。

相關(guān)文章

最新評論

无棣县| 进贤县| 汨罗市| 茂名市| 曲水县| 普陀区| 克拉玛依市| 拜城县| 崇义县| 涞水县| 灵丘县| 大邑县| 夏津县| 宜都市| 元朗区| 临朐县| 唐河县| 读书| 青田县| 林州市| 临邑县| 嘉黎县| 辉南县| 深水埗区| 夏津县| 连江县| 华安县| 泗阳县| 达日县| 进贤县| 余庆县| 武川县| 宾阳县| 宿松县| 龙门县| 泰宁县| 防城港市| 兴山县| 兴和县| 绵竹市| 临朐县|