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# Importación de GeoJSON con un array de objetos profundamente anidado
> “Importación de GeoJSON con un array de objetos profundamente anidado“
{frontMatter.description}
## Pregunta
¿Cómo importo GeoJSON con un array anidado de objetos?
## Respuesta
Para este tutorial, usaremos datos abiertos disponibles públicamente [aquí](https://opendata.esri.es/datasets/ComunidadSIG::municipios-ign/explore?location=39.536006%2C-0.303882%2C6.57). Puede encontrar una copia [aquí](https://datasets-documentation.s3.eu-west-3.amazonaws.com/geoJSON/Municipios.geojson).
1. Descargue los datos en formato GeoJSON y cambie el nombre del archivo a `geojson.json`.
2. Comprenda la estructura.
```sql theme={null}
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) │
│ │ ) │
│ │ ) │
└──────────┴──────────────────────────────────────────────────────────────────────────────────────────────┘
```
3. Cree una tabla para almacenar las filas de GeoJSON.
Aquí, el requisito es generar una fila para cada `object` del `features array`.
El tipo de dato inferido para el campo `geometry` sugiere que corresponde al [tipo de dato](/es/reference/data-types/geo#multipolygon) **MultiPolygon** de ClickHouse.
```sql theme={null}
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;
```
4. Prepare los datos.
El objetivo principal de la consulta es verificar que obtenemos una fila por cada **objeto** del **array `features`**.
El campo `features.geometry.coordinates` está comentado para que el conjunto de resultados sea más legible.
```sql theme={null}
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 │
└───────────────────┴────────────────┴─────────┴───────────────────────────────┴─────────────┴────┴──────────────────────────┴─────────────┴───────────────────────┴─────────┴─────────┴─────────┴───────────┴────────────────────┴───────────────────────┴──────────────┘
```
5. Inserte los datos.
```sql theme={null}
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
```
Aquí aparece el siguiente error:
```
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):
```
Esto se debe al análisis de `features.geometry.coordinates`.
6. Comprobemos su tipo de dato.
```sql theme={null}
SELECT DISTINCT toTypeName(features.geometry.coordinates) AS geometry
FROM file('municipios_ign.geojson', 'JSON')
ARRAY JOIN features
┌─geometry──────────────────────────────────────┐
│ Array(Array(Array(Array(Nullable(Float64))))) │
└───────────────────────────────────────────────┘
```
Se puede solucionar convirtiendo `multipolygon.properties.coordinates` a `Array(Array(Array(Tuple(Float64,Float64))))`.
Para ello, podemos usar la función [arrayMap(func,arr1,...)](/es/reference/functions/regular-functions/array-functions#arrayMap).
```sql theme={null}
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))))) │
└──────────────────────────────────────────────────────────────────┘
```
7. Inserte los datos.
```sql theme={null}
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;
```
```sql theme={null}
SELECT count()
FROM geojson
┌─count()─┐
│ 8205 │
└─────────┘
SELECT DISTINCT toTypeName(geometry)
FROM geojson
┌─toTypeName(geometry)─┐
│ MultiPolygon │
└──────────────────────┘
```
### Conclusión
Trabajar con JSON puede ser una tarea compleja. En este tutorial se abordó un caso en el que un array de objetos anidados podía dificultar aún más esta tarea.
Para cualquier otro requisito relacionado con JSON, consulta nuestra [documentación](/es/guides/clickhouse/data-formats/json/intro).