如何使用 bookshelf.js 或 knex 在 MySQL 中查询按距离与纬度、经度坐标排序的地点？

Question

Is it possible to search nearest places in mysql by using Bookshelf.js, or Knex? And, if yes, how to do it correct?

UPD: I'm not strong with raw mysql queries, and can't find how to search with lat, lng in Bookshelf and knex.

For example, i have places table with:

• title
• address
• lat
• lng.

What query i should use to get all places in 10 miles radius from Point(lat, lng)?

thanks.

Answer 1

After some research i found working solution:

const {lat, lng} = req.params;

const X1 = +lat - 10,
      Y1 = +lng - 10,
      X2 = +lat + 10,
      Y2 = +lng + 10;


const distanceInMilesSql = `( 3959 * acos( cos( radians(${+lat}) ) 
          * cos( radians( place.lat ) ) 
          * cos( radians( place.lng ) - radians(${+lng}) ) 
          + sin( radians(${+lat}) ) 
          * sin( radians( place.lat ) ) ) ) AS distance 
        `;

const places = await new Place().query(qb => {
    qb.whereBetween('lat', [X1, X2]);
    qb.whereBetween('lng', [Y1, Y2]);
    qb.column(['*', Bookshelf.knex.raw(distanceInMilesSql)]);
    qb.having('distance', '<', 10);
}).fetchAll({withRelated: [
    'place_specific_fields',
    'state',
    'media'
]});

Answer 2

Demo

http://rextester.com/NDOR4479

SQL

SELECT *,
       ACOS(SIN(RADIANS(:lat)) * SIN(RADIANS(lat)) + COS(RADIANS(:lat)) * COS(RADIANS(lat))
       * COS(RADIANS(lng - :lng))) * 3959 AS distance
FROM places
WHERE  ACOS(SIN(RADIANS(:lat)) * SIN(RADIANS(lat)) + COS(RADIANS(:lat)) * COS(RADIANS(lat))
       * COS(RADIANS(lng - :lng))) * 3959 <= 10
ORDER BY distance;

Notes

The above uses the Spherical Law of Cosines where :lat and :lng are the latitude and longitude values from Point and 3959 is the Earth radius in miles.

Answer 3

If it helps anyone, here's some code I use (Strapi + MySQL):

1. Query for events
2. Join locations into events , where id matches
3. Gets anything within 5km (5000 meters) of the user

On a side note: As a Strapi user, a raw query like this negates the high-level functionality that Strapi auto-builds for the events model. ie Strapi url filtering like &Cost_gte=20 won't work. I'm still working on how to get around this and avoid having to build an entire custom controller from scratch (all just to have distance filtering?).

Code:

const knex = strapi.connections.default
const result = await knex('events')
    .join('locations', 'events.Location', 'locations.id')
    .where(knex.raw(                
        `round(st_distance_sphere(
            st_geomfromtext(CONCAT('POINT(',locations.Longitude, ' ',locations.Latitude,')')),
            st_geomfromtext(CONCAT('POINT(` + ctx.query.Longitude + ` ` + ctx.query.Latitude + `)'))
        )) <= 5000`
    ))
    return result

Answer 4

You don't make it clear in your question, but I believe that the Bookshelf.js library works as a layer above PostgreSQL, which means that you have access to geometric data types . These can make use of these special operations . The search could be entirely SQL based, so without further context I can simply offer the following:

Combine the latitude and longitude into a single data piece of type point (using the decimal form of the latitude and longitude). Here I will refer to that as coord .

With the proper data in order, you can do a query of:

SELECT p.*, (point'(@origin_long,$origin_lat)' <-> `coord`) distance
FROM `places` p
WHERE circle '((@origin_long, @origin_lat),@radius)' @> `coord`
ORDER BY distance;

If the data structures are set right, this should return a list, ordered by distance, of all pairs of coordinates within a given radius. You can set the coordinates at the top of this function, or maybe even wrap it in a stored procedure (if you don't mind the overhead).

For further reading, I know that PostgreSQL has an " Earth Distance " function as well, so if you are looking to include the calculation of true distance traveled between points, it might be useful!