sqlite

go-whosonfirst-spatial-sqlite

Important

This is work in progress. It may change, probably has bugs and isn't properly documented yet.

The goal is to have a package that conforms to the database.SpatialDatabase interface using mattn/go-sqlite3 and SQLite's RTree extension.

Also, this is not as fast as it should be. This is largely with the way WOF records are inflated and passed around in order to support GeoJSON output. There is an open ticket to address this.

Example

package main

import (
	"context"
	"encoding/json"
	"fmt"
	_ "github.com/whosonfirst/go-whosonfirst-spatial-sqlite"
	"github.com/whosonfirst/go-whosonfirst-spatial/database"
	"github.com/whosonfirst/go-whosonfirst-spatial/filter"
	"github.com/whosonfirst/go-whosonfirst-spatial/geo"
	"github.com/whosonfirst/go-whosonfirst-spatial/properties"
	"github.com/whosonfirst/go-whosonfirst-spr"
)

func main() {

	database_uri := "sqlite://?dsn=whosonfirst.db"
	properties_uri := "sqlite://?dsn=whosonfirst.db"
	latitude := 37.616951
	longitude := -122.383747

	props := []string{
		"wof:concordances",
		"wof:hierarchy",
		"sfomuseum:*",
	}

	ctx := context.Background()
	
	db, _ := database.NewSpatialDatabase(ctx, *database_uri)
	pr, _ := properties.NewPropertiesReader(ctx, *properties_uri)
	
	c, _ := geo.NewCoordinate(*longitude, *latitude)
	f, _ := filter.NewSPRFilter()
	r, _ := db.PointInPolygon(ctx, c, f)

	r, _ = pr.PropertiesResponseResultsWithStandardPlacesResults(ctx, r, props)

	enc, _ := json.Marshal(r)
	fmt.Println(string(enc))
}

Error handling removed for the sake of brevity.

Interfaces

This package implements the following go-whosonfirst-spatial interfaces.

spatial.SpatialDatabase

import (
	"github.com/whosonfirst/go-whosonfirst-spatial/database"
	_ "github.com/whosonfirst/go-whosonfirst-spatial-sqlite"       
)

db, err := database.NewSpatialDatabase(ctx, "sqlite://?dsn={DSN}")

spatial.PropertiesReader

import (
	"github.com/whosonfirst/go-whosonfirst-spatial/properties"
	_ "github.com/whosonfirst/go-whosonfirst-spatial-sqlite"       
)

pr, err := properties.NewPropertiesReader(ctx, "sqlite://?dsn={DSN}")

Tools

query

$> ./bin/query -h
Usage of ./bin/query:
  -database-uri string
    	...
  -latitude float
    	...
  -longitude float
    	...
  -properties value
    	...
  -properties-uri string
    	...

For example:

$> ./bin/query \
	-database-uri 'sqlite://?dsn=/usr/local/data/sfomuseum-data-architecture.db' \
	-properties-uri 'sqlite://?dsn=/usr/local/data/sfomuseum-data-architecture.db' \
	-latitude 37.616951 \
	-longitude -122.383747 \
	-properties 'wof:hierarchy' \
	-properties 'sfomuseum:*' \
| jq

{
  "properties": [
    {
      "mz:is_ceased": 1,
      "mz:is_current": 0,
      "mz:is_deprecated": 0,
      "mz:is_superseded": 1,
      "mz:is_superseding": 1,
      "mz:latitude": 37.617475,
      "mz:longitude": -122.383371,
      "mz:max_latitude": 37.61950174060331,
      "mz:max_longitude": -122.38139655218178,
      "mz:min_latitude": 37.61615511156664,
      "mz:min_longitude": -122.3853565208227,
      "mz:uri": "https://data.whosonfirst.org/115/939/616/5/1159396165.geojson",
      "sfomuseum:is_sfo": 1,
      "sfomuseum:placetype": "terminal",
      "sfomuseum:terminal_id": "CENTRAL",
      "wof:country": "US",
      "wof:hierarchy": [
        {
          "building_id": 1159396339,
          "campus_id": 102527513,
          "continent_id": 102191575,
          "country_id": 85633793,
          "county_id": 102087579,
          "locality_id": 85922583,
          "neighbourhood_id": -1,
          "region_id": 85688637,
          "wing_id": 1159396165
        }
      ],
      "wof:id": 1159396165,
      "wof:lastmodified": 1547232162,
      "wof:name": "Central Terminal",
      "wof:parent_id": 1159396339,
      "wof:path": "115/939/616/5/1159396165.geojson",
      "wof:placetype": "wing",
      "wof:repo": "sfomuseum-data-architecture",
      "wof:superseded_by": [
        1159396149
      ],
      "wof:supersedes": [
        1159396171
      ]
    },

    ... and so on
   }
]   

Note: This assumes a database that was previously indexed using the whosonfirst/go-whosonfirst-sqlite-features wof-sqlite-index-features tool. For example:

$> ./bin/wof-sqlite-index-features -rtree -geojson -dsn /tmp/test.db -mode repo:// /usr/local/data/sfomuseum-data-architecture/

See also

• https://www.sqlite.org/rtree.html
• https://github.com/whosonfirst/go-whosonfirst-spatial
• https://github.com/whosonfirst/go-whosonfirst-sqlite
• https://github.com/whosonfirst/go-whosonfirst-sqlite-features