google-bigquery - 纬度和经度 - 使用 bigquery 查找城市和州

Question

我的表格中有纬度和经度信息。我想使用 bigquery 使用纬度和经度信息查找最近的城市和州名称。

Answer 1

希望下面的简单示例能为您提供良好的入门方向

SELECT 
  yourLon, yourLat, ROUND(distance) AS distance, city, state 
FROM (
  SELECT 
    yourLon, yourLat, distance, city, state, 
    ROW_NUMBER() OVER (PARTITION BY yourLon, yourLat ORDER BY distance) AS win
  FROM 
  JS((
    // input table
    SELECT 
      points.yourLon AS yourLon, 
      points.yourLat AS yourLat, 
      cities.city AS city, 
      cities.state AS state, 
      cities.lon AS lon, 
      cities.lat AS lat
    FROM (
      SELECT city, state, lon, lat FROM
        (SELECT 'acampo' AS city, 'ca' AS state,  -121.23200000000001 AS lon, 38.1964 AS lat), 
        (SELECT 'adelanto ' AS city,  'ca' AS state,    -117.48 AS lon,   34.5894  AS lat), 
        (SELECT 'agoura hills ' AS city,  'ca' AS state,    -118.76 AS lon,   34.1445 AS lat), 
        (SELECT 'alameda  ' AS city,  'ca' AS state,    -122.26 AS lon,   37.7606 AS lat),  
        (SELECT 'alamo  ' AS city,  'ca' AS state,    -122.019 AS lon,  37.8525 AS lat),  
        (SELECT 'albany ' AS city,  'ca' AS state,    -122.294 AS lon,  37.8882 AS lat),  
        (SELECT 'albion ' AS city,  'ca' AS state,    -123.705 AS lon,  39.2141 AS lat),  
        (SELECT 'alhambra ' AS city,  'ca' AS state,    -118.12999999999998 AS lon,   34.0899 AS lat),  
        (SELECT 'aliso viejo  ' AS city,  'ca' AS state,    -117.736 AS lon,  33.5761 AS lat),  
        (SELECT 'altadena ' AS city,  'ca' AS state,    -118.14000000000001 AS lon,   34.1884 AS lat),  
        (SELECT 'anaheim  ' AS city,  'ca' AS state,    -117.92667647058823 AS lon,   33.83603382352941 AS lat),  
        (SELECT 'anderson ' AS city,  'ca' AS state,    -122.299 AS lon,  40.469 AS lat),    
        (SELECT 'angels camp  ' AS city,  'ca' AS state,    -120.625 AS lon,  38.0746 AS lat),  
        (SELECT 'antelope ' AS city,  'ca' AS state,    -121.38099999999999 AS lon,   38.6861 AS lat),  
        (SELECT 'antioch  ' AS city,  'ca' AS state,    -121.806 AS lon,  37.99594999999999 AS lat),  
        (SELECT 'anza ' AS city,  'ca' AS state,    -116.743 AS lon,  33.5886 AS lat),  
        (SELECT 'apple valley ' AS city,  'ca' AS state,    -117.19333333333333 AS lon,   34.47484444444444 AS lat),  
        (SELECT 'aptos  ' AS city,  'ca' AS state,    -121.877 AS lon,  36.9926 AS lat),  
        (SELECT 'arbuckle ' AS city,  'ca' AS state,    -122.015 AS lon,  39.0326 AS lat),  
        (SELECT 'arcadia  ' AS city,  'ca' AS state,    -118.04199999999999 AS lon,   34.1325 AS lat)
    ) AS cities
    CROSS JOIN (
      SELECT yourLon, yourLat FROM
      (SELECT -122 AS yourLon, 38 AS yourLat),
      (SELECT -117 AS yourLon, 34 AS yourLat),
    ) AS points
  ) ,
  // input columns
  yourLon, yourLat, city, state, lon, lat,
  // output schema
  "[{name: 'yourLon', type: 'float'},
  {name: 'yourLat', type: 'float'},
  {name: 'city', type: 'string'},
  {name: 'state', type: 'string'},
  {name: 'distance', type: 'float'}]",
  // function
  "function(r, emit){
    var R = 3959; // Radius of the earth in miles
    var dLat = deg2rad(r.lat-r.yourLat);  
    var dLon = deg2rad(r.lon-r.yourLon); 
    var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
      Math.cos(deg2rad(r.yourLat)) * Math.cos(deg2rad(r.lat)) * 
      Math.sin(dLon/2) * Math.sin(dLon/2); 
    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
    emit({yourLon: r.yourLon, yourLat: r.yourLat, city: r.city, state: r.state, distance: R * c});

    function deg2rad(deg) {
      return deg * (Math.PI/180)
    }
  }"
  )
)
WHERE win = 1

结果如下

yourLon yourLat distance    city    state    
-117.0  34.0    32.0        anza    ca   
-122.0  38.0    10.0        alamo   ca