Simon Willison’s Weblog

5 items tagged “spatialite”

Things I learned about shapefiles building shapefile-to-sqlite

The latest in my series of x-to-sqlite tools is shapefile-to-sqlite. I learned a whole bunch of things about the ESRI shapefile format while building it.

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geojson-to-sqlite (via) I just put out the first release of geojson-to-sqlite—a CLI tool that can convert GeoJSON files (consisting of a Feature or a set of features in a FeatureCollection) into a table in a SQLite database. If you use the --spatialite option it will initalize the table with SpatiaLite and store the geometries in a spacially indexed geometry field—without that option it stores them as GeoJSON. # 31st January 2020, 6:40 am

SpatiaLite — Datasette documentation. Datasette’s documentation now includes extensive coverage of the SpatiaLite extension for SQLite: how to install it, how to import latitude/longitude points, shapefiles and GeoJSON data into SpatiaLite tables, and how to run SQL queries against it that take advantage of spatial indexes. I’m learning SpatiaLite at the moment and filling out the documentation with each new trick I learn as I go—as Mark Pilgrim once taught me, the best way to learn a new technology is to write about it. # 30th May 2018, 4:34 am

VirtualKNN for SpatiaLite. This looks amazing: a special virtual table shipped as part of SpatiaLite 4.4.0 which implements a fast, R-Tree backed mechanism for finding the X nearest points against a geospatial database table. There’s just one catch: it’s only available in 4.4.0, but the most recent “stable” release of SpatiaLite is 4.3.0a from September 2015 so the version you get if you install from apt-get or homebrew doesn’t yet have this functionality. I’d love to figure out a neat way to package and distribute this along with Datasette. I’d also like to figure out a clean way to ship a more recent version of SQLite than the one that is currently packaged with Python 3 (3.16.2, where the latest SQLite release is 3.23.1). # 21st May 2018, 9:23 pm

GeoCouch: Geospatial queries with CouchDB. Interesting approach: uses “external2”, a branch that allows external services to be called from CouchDB. SQLite’s SpatiaLite extension is then used as an external spacial index. # 27th October 2008, 11:48 pm