如何使用MySQL 8 ST_Distance計算兩個坐標（從Google地圖）之間的距離？

Question

我的數據庫中有一張表格，用於存儲Google地圖中的位置以及它們返回的坐標。 以前，我將lat和lng存儲為小數點，並且在將MySQL版本升級到8后，發現存在預定義的數據類型和函數來處理坐標和距離計算。 我創建了下表，並從Google Map中插入了一些隨機值。

CREATE TABLE `Location` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `lat` varchar(50) NOT NULL,
  `lng` varchar(50) NOT NULL,
  `coordinates` point NOT NULL,
  `name` varchar(500) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_lat_lng` (`lat`,`lng`),
  SPATIAL KEY `sk_coordinates` (`coordinates`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

插入樣本數據

INSERT INTO Location (name, lat, lng, coordinates)
SELECT 'Thayyeni Koomban', '12.33984592973732', '75.41285991668701', POINT(12.33984592973732, 75.41285991668701) UNION
SELECT 'Tejaswini river rafting', '12.29208143873455', '75.4130744934082', POINT(12.29208143873455, 75.4130744934082) UNION
SELECT 'Mossy Forest, Cameron Highlands', '4.5242225', '101.38192709999998', POINT(4.5242225, 101.38192709999998) UNION
SELECT 'Dhanushkodi Point', '9.152226599999999', '79.44291569999996', POINT(9.152226599999999, 79.44291569999996) UNION
SELECT 'KL Sentral', '3.13333', '101.68667000000005', POINT(3.13333, 101.68667000000005) UNION
SELECT 'Kozhippara Waterfalls', '11.3537295', '76.10803290000001', POINT(11.3537295, 76.10803290000001) UNION
SELECT 'Laguna Honda Hospital and Rehabilitation Center', '37.7492806', '-122.45702240000003', POINT(37.7492806, -122.45702240000003) UNION
SELECT 'Singapore Zoo', '1.4043485', '103.79302299999995', POINT(1.4043485, 103.79302299999995) UNION
SELECT 'Taj Mahal', '27.1750151', '78.04215520000002', POINT(27.1750151, 78.04215520000002) UNION
SELECT 'Sea View Point', '11.2643567', '75.76153939999995', POINT(11.2643567, 75.76153939999995) UNION
SELECT 'Club Mahindra Ashtamudi', '8.965749299999997', '76.57136119999996', POINT(8.965749299999997, 76.57136119999996) UNION
SELECT 'Kollam Beach', '8.8756778', '76.58891629999994', POINT(8.8756778, 76.58891629999994) UNION
SELECT 'Tropical Islands', '52.03892399999999', '13.748616999999967', POINT(52.03892399999999, 13.748616999999967) UNION
SELECT 'Taroko National Park', '24.15870679999999', '121.62162969999997', POINT(24.15870679999999, 121.62162969999997) UNION
SELECT 'Lake Tyrrell', '-35.2553505', '142.8419824', POINT(-35.2553505, 142.8419824) UNION
SELECT 'Karthika Regency', '10.0192948', '76.30539509999994', POINT(10.0192948, 76.30539509999994) UNION
SELECT 'Sentosa', '1.2494041', '103.83032090000006', POINT(1.2494041, 103.83032090000006) UNION
SELECT 'Kovalam Beach', '12.7902597', '80.25390390000007', POINT(12.7902597, 80.25390390000007) UNION
SELECT 'Torres del Paine National Park', '-50.9423262', '-73.40678789999998', POINT(-50.9423262, -73.40678789999998) UNION
SELECT 'Niagara Falls', '43.0828162', '-79.07416289999998', POINT(43.0828162, -79.07416289999998);

了解到Google坐標使用3857的SRID，因此使用lat和lng的不同組合創建了以下查詢以生成點。 但是距離似乎都不是准確的。

SELECT 
    name, 
    lat, 
    lng, 
    ST_Distance(ST_SRID(coordinates, 3857), ST_GeomFromText('POINT(10.0120262 76.3586236)', 3857)) AS distance,
    ST_Distance(ST_SRID(POINT(lat, lng), 3857), ST_GeomFromText('POINT(10.0120262 76.3586236)', 3857)) AS lat_lng,
    ST_Distance(ST_SRID(POINT(lng, lat), 3857), ST_GeomFromText('POINT(10.0120262 76.3586236)', 3857)) AS lng_lat_first,
    ST_Distance(ST_SRID(POINT(lng, lat), 3857), ST_GeomFromText('POINT(76.3586236 10.0120262)', 3857)) AS lng_lat_all,
    ST_Distance(ST_SRID(POINT(lng, lat), 3857), ST_SRID(POINT(76.3586236, 10.0120262), 3857)) AS lng_lat_all_x,
    ST_Distance(ST_SRID(POINT(lng, lat), 3857), ST_SRID(POINT(10.0120262, 76.3586236), 3857)) AS lng_lat_all_y, 
    ST_Distance(ST_SRID(POINT(lat, lng), 3857), ST_SRID(POINT(10.0120262, 76.3586236), 3857)) AS lng_lat_all_z   
from test.Location;

我是以正確的方式進行操作還是丟失了某些東西？ 提前致謝。

Answer 1

我不確定。但是ST_Distance接受兩個參數。這里是三個參數。

 mysql> SET @g1 = Point(1,1); mysql> SET @g2 = Point(2,2); mysql> SELECT ST_Distance(@g1, @g2); .