Comment importer du GeoJSON avec un tableau d’objets imbriqués ?
Pour ce tutoriel, nous utiliserons des données ouvertes disponibles publiquement ici. Une copie est disponible ici.
-
Téléchargez les données au format GeoJSON et renommez le fichier en
geojson.json.
-
Examinez la structure.
DESCRIBE TABLE file('geojson.json', 'JSON')
┌─name─────┬─type─────────────────────────────────────────────────────────────────────────────────────────┐
│ type │ Nullable(String) │
│ name │ Nullable(String) │
│ crs │ Tuple( properties Tuple(name Nullable(String)),type Nullable(String)) │
│ features │ Array(Tuple( │
│ │ geometry Tuple(coordinates Array(Array(Array(Array(Nullable(Float64))))), │
│ │ type Nullable(String)), │
│ │ properties Tuple( CODIGOINE Nullable(String), │
│ │ CODNUT1 Nullable(String), │
│ │ CODNUT2 Nullable(String), │
│ │ CODNUT3 Nullable(String), │
│ │ FID Nullable(Int64), │
│ │ INSPIREID Nullable(String), │
│ │ NAMEUNIT Nullable(String), │
│ │ NATCODE Nullable(String), │
│ │ SHAPE_Area Nullable(Float64), │
│ │ SHAPE_Length Nullable(Float64) │
│ │ ), │
│ │ type Nullable(String) │
│ │ ) │
│ │ ) │
└──────────┴──────────────────────────────────────────────────────────────────────────────────────────────┘
- Créez une table pour stocker les lignes GeoJSON.
L’objectif ici est de générer une ligne pour chaque objet du tableau features.
Le type de données inféré pour le champ geometry indique qu’il correspond au type de données MultiPolygon de ClickHouse.
create table geojson
(
type String,
name String,
crsType String,
crsName String,
featureType String,
id Int64,
inspiredId String,
natCode String,
nameUnit String,
codNut1 String,
codNut2 String,
codNut3 String,
codigoIne String,
shapeLength Float64,
shapeArea Float64,
geometryType String,
geometry MultiPolygon
)
engine = MergeTree
order by id;
- Préparez les données.
L’objectif principal de la requête est de vérifier que nous obtenons une ligne pour chaque objet du tableau features.
Le champ features.geometry.coordinates est mis en commentaire afin de rendre le jeu de résultats plus lisible.
SELECT
type AS type,
name AS name,
crs.type AS crsType,
crs.properties.name AS crsName,
features.type AS featureType,
features.properties.FID AS id,
features.properties.INSPIREID AS inspiredId,
features.properties.NATCODE AS natCode,
features.properties.NAMEUNIT AS nameUnit,
features.properties.CODNUT1 AS codNut1,
features.properties.CODNUT2 AS codNut2,
features.properties.CODNUT3 AS codNut3,
features.properties.CODIGOINE AS codigoIne,
features.properties.SHAPE_Length AS shapeLength,
features.properties.SHAPE_Area AS shapeArea,
features.geometry.type AS geometryType
--,features.geometry.coordinates
FROM file('municipios_ign.geojson', 'JSON')
ARRAY JOIN features
LIMIT 5
┌─type──────────────┬─name───────────┬─crsType─┬─crsName───────────────────────┬─featureType─┬─id─┬─inspiredId───────────────┬─natCode─────┬─nameUnit──────────────┬─codNut1─┬─codNut2─┬─codNut3─┬─codigoIne─┬────────shapeLength─┬─────────────shapeArea─┬─geometryType─┐
│ FeatureCollection │ Municipios_IGN │ name │ urn:ogc:def:crs:OGC:1.3:CRS84 │ Feature │ 1 │ ES.IGN.SIGLIM34081616266 │ 34081616266 │ Villarejo-Periesteban │ ES4 │ ES42 │ ES423 │ 16266 │ 0.2697476997304121 │ 0.0035198414406406673 │ MultiPolygon │
│ FeatureCollection │ Municipios_IGN │ name │ urn:ogc:def:crs:OGC:1.3:CRS84 │ Feature │ 2 │ ES.IGN.SIGLIM34081616269 │ 34081616269 │ Villares del Saz │ ES4 │ ES42 │ ES423 │ 16269 │ 0.4476083901269905 │ 0.00738179315030249 │ MultiPolygon │
│ FeatureCollection │ Municipios_IGN │ name │ urn:ogc:def:crs:OGC:1.3:CRS84 │ Feature │ 3 │ ES.IGN.SIGLIM34081616270 │ 34081616270 │ Villarrubio │ ES4 │ ES42 │ ES423 │ 16270 │ 0.3053942273994179 │ 0.0029777582813496337 │ MultiPolygon │
│ FeatureCollection │ Municipios_IGN │ name │ urn:ogc:def:crs:OGC:1.3:CRS84 │ Feature │ 4 │ ES.IGN.SIGLIM34081616271 │ 34081616271 │ Villarta │ ES4 │ ES42 │ ES423 │ 16271 │ 0.2831226979821184 │ 0.002680273189024594 │ MultiPolygon │
│ FeatureCollection │ Municipios_IGN │ name │ urn:ogc:def:crs:OGC:1.3:CRS84 │ Feature │ 5 │ ES.IGN.SIGLIM34081616272 │ 34081616272 │ Villas de la Ventosa │ ES4 │ ES42 │ ES423 │ 16272 │ 0.5958276749246777 │ 0.015354885085133583 │ MultiPolygon │
└───────────────────┴────────────────┴─────────┴───────────────────────────────┴─────────────┴────┴──────────────────────────┴─────────────┴───────────────────────┴─────────┴─────────┴─────────┴───────────┴────────────────────┴───────────────────────┴──────────────┘
- Insérez les données.
INSERT INTO geojson
SELECT
type AS type,
name AS name,
crs.type AS crsType,
crs.properties.name AS crsName,
features.type AS featureType,
features.properties.FID AS id,
features.properties.INSPIREID AS inspiredId,
features.properties.NATCODE AS natCode,
features.properties.NAMEUNIT AS nameUnit,
features.properties.CODNUT1 AS codNut1,
features.properties.CODNUT2 AS codNut2,
features.properties.CODNUT3 AS codNut3,
features.properties.CODIGOINE AS codigoIne,
features.properties.SHAPE_Length AS shapeLength,
features.properties.SHAPE_Area AS shapeArea,
features.geometry.type AS geometryType,
features.geometry.coordinates as geometry
FROM file('municipios_ign.geojson', 'JSON')
ARRAY JOIN features
Code: 53. DB::Exception: Received from localhost:9000. DB::Exception: ARRAY JOIN requires array or map argument. (TYPE_MISMATCH)
Received exception from server (version 24.1.2):
features.geometry.coordinates.
- Vérifions son type de données.
SELECT DISTINCT toTypeName(features.geometry.coordinates) AS geometry
FROM file('municipios_ign.geojson', 'JSON')
ARRAY JOIN features
┌─geometry──────────────────────────────────────┐
│ Array(Array(Array(Array(Nullable(Float64))))) │
└───────────────────────────────────────────────┘
multipolygon.properties.coordinates au type Array(Array(Array(Tuple(Float64,Float64)))).
Pour ce faire, nous pouvons utiliser la fonction arrayMap(func,arr1,…).
SELECT distinct
toTypeName(
arrayMap(features.geometry.coordinates->
arrayMap(features.geometry.coordinates->
arrayMap(features.geometry.coordinates-> (features.geometry.coordinates[1],features.geometry.coordinates[2])
,features.geometry.coordinates),
features.geometry.coordinates),
features.geometry.coordinates)
) as toTypeName
FROM file('municipios_ign.geojson', 'JSON')
ARRAY JOIN features;
┌─toTypeName───────────────────────────────────────────────────────┐
│ Array(Array(Array(Tuple(Nullable(Float64), Nullable(Float64))))) │
└──────────────────────────────────────────────────────────────────┘
- Insérez les données.
INSERT INTO geojson
SELECT
type as type,
name as name,
crs.type as crsType,
crs.properties.name as crsName,
features.type as featureType,
features.properties.FID id,
features.properties.INSPIREID inspiredId,
features.properties.NATCODE natCode,
features.properties.NAMEUNIT nameUnit,
features.properties.CODNUT1 codNut1,
features.properties.CODNUT2 codNut2,
features.properties.CODNUT3 codNut3,
features.properties.CODIGOINE codigoIne,
features.properties.SHAPE_Length shapeLength,
features.properties.SHAPE_Area shapeArea,
features.geometry.type geometryType,
arrayMap(features.geometry.coordinates->
arrayMap(features.geometry.coordinates->
arrayMap(features.geometry.coordinates-> (features.geometry.coordinates[1],features.geometry.coordinates[2]),features.geometry.coordinates)
,features.geometry.coordinates)
,features.geometry.coordinates) geometry
FROM file('municipios_ign.geojson', 'JSON')
ARRAY JOIN features;
SELECT count()
FROM geojson
┌─count()─┐
│ 8205 │
└─────────┘
SELECT DISTINCT toTypeName(geometry)
FROM geojson
┌─toTypeName(geometry)─┐
│ MultiPolygon │
└──────────────────────┘
