KB article that shows how to import GeoJSON with a deeply nested object array. #2926
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| How do I import GeoJSON with a nested object array? | ||
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| ### Answer | ||
| For this tutorial, we will use open data publicly available [here](https://opendata.esri.es/datasets/ComunidadSIG::municipios-ign/explore?location=39.536006%2C-0.303882%2C6.57). |
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Will this link expire or change? It looks very specific, perhaps we could recommend they go to a specific website rather than this exact location URL.
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This link comes from a real use case we discussed on the Community Slack channel. To ensure reproducibility and avoid relying on the URL, I recommend downloading the GeoJSON and making it available in our public bucket, similar to how we provide the New York Taxi Data here.
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There is this site https://geojson.io that offers geoJSON rendering.
This is what the same dataset looks like:
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| │ MultiPolygon │ | ||
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In addition to the count() query, it may be good to demo something complex to show the analytical power of geo data in ClickHouse. Perhaps something that filters on one of the many columns? We also have some functions for measuring distance, but I don't think they can be easily applied to the polygon data
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I'll look into:
- https://clickhouse.com/docs/en/sql-reference/functions/geo/polygons#polygonareaspherical
- https://clickhouse.com/docs/en/sql-reference/functions/geo/polygons#polygonperimeterspherical
- https://clickhouse.com/docs/en/sql-reference/functions/geo/polygons#polygonareacartesian
- https://clickhouse.com/docs/en/sql-reference/functions/geo/polygons#polygonperimetercartesian
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@SpencerTorres One of the questions we have is whether this KB is still relevant since we have the JSON data type now. @allegrinisante is the author of the KB and is looking to review and possibly adapt it to the new capabilities. But was just wondering what your thoughts are. |
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Explicitly mapping structures with tuples and nested still has its place - mainly for performance. JSON is for dynamic data. Can we address the first comment of @SpencerTorres @linhgiang24 re the link. this is the only blocker to merging. Comment 2 re better example query is not a blocker but a nice to have. |
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@gingerwizard, I've secured the geoJSON in my bucket. Let me know if you're okay with saving it on S3 under |
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@allegrinisante please yes move to the dataset-documentation bucket! |
The file is available here: s3://datasets-documentation/geoJSON/Municipios.geojson |
Can we use this in the docs @allegrinisante ? i've made public at https://datasets-documentation.s3.eu-west-3.amazonaws.com/geoJSON/Municipios.geojson |
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Modified link, if this renders ok on build i'll merge. Follow up with enhancements @allegrinisante as discussed. |
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This needs to be rebased to build - the latest clickhouse repo docs are looking for a file which has been added after this PR was raised. |
Summary
This KB article walks through an example of importing GeoJSON with a deeply nested object array.