السؤال
الإجابة
-
نزّل البيانات بتنسيق GeoJSON وأعد تسمية الملف إلى
geojson.json. - تعرّف على البنية.
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) │
│ │ ) │
│ │ ) │
└──────────┴──────────────────────────────────────────────────────────────────────────────────────────────┘
- أنشئ جدولًا لتخزين صفوف GeoJSON.
المطلوب هنا هو إنشاء صف لكل
كائن في مصفوفة features“.
ويشير نوع البيانات المُستنتَج للحقل geometry إلى أنه يقابل MultiPolygon نوع البيانات في 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;
- حضّر البيانات.
الهدف الرئيسي من الاستعلام هو التحقق من حصولنا على صف واحد لكل كائن في مصفوفة
features.
وُضع الحقل
features.geometry.coordinates ضمن تعليق لجعل مجموعة النتائج أكثر قابلية للقراءة.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 │
└───────────────────┴────────────────┴─────────┴───────────────────────────────┴─────────────┴────┴──────────────────────────┴─────────────┴───────────────────────┴─────────┴─────────┴─────────┴───────────┴────────────────────┴───────────────────────┴──────────────┘
- أدرِج البيانات.
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.
- لنتحقق من نوع البيانات الخاص به.
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 إلى Array(Array(Array(Tuple(Float64,Float64)))).
ولتحقيق ذلك، يمكننا استخدام الدالة 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))))) │
└──────────────────────────────────────────────────────────────────┘
- أدخِل البيانات.
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 │
└──────────────────────┘