本文介绍了如何从geojson对象查询的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

在下面发布的查询中,我想查询以下信息

in the below posted query i want to query the following information

    ST_Transform(ST_SetSRID(ST_GeomFromGeoJSON(feature->>'geometry'),4326),25832) AS LIDARDataPolygonsAsGeometry

featuresCollection 是一个 geojson 对象.

The featuresCollection is a geojson object.

请告诉我如何从 geojson 对象中查询

Please let me know how to query from a geojson object

    query="""
            WITH data AS (
                SELECT '{featuresCollection}'::json AS featuresCollection
            )
            SELECT
                LIDARDataPolygonsAsGeometry,
            FROM (
                SELECT
                    ST_Transform(ST_SetSRID(ST_GeomFromGeoJSON(feature->>'geometry'),4326),25832) AS LIDARDataPolygonsAsGeometry

            FROM (SELECT json_array_elements(featuresCollection->'features') AS feature
                    FROM data) AS f) j
            GROUP BY LIDARDataPolygonsAsGeometry
        """.format(table=config['PostgreDB']['table_name_test'], width=config['Grid']['cell_width'], height=config['Grid']['cell_height'],bufferRadius=config['Grid']['buffer_radius'],featuresCollection=featuresCollection)

推荐答案

只需在子查询中解压您的特征集合,提取几何图形并应用您想要的转换,例如来自名为 t 的表,其中包含一个包含 GeoJSON 字符串的列 geojson:

Just unpack your feature collection in a subquery, extract the geometries and apply the transformation you want, e.g. from a table called t with a column geojson containing GeoJSON strings:

SELECT
 ST_Transform(
  ST_SetSRID(
    ST_GeomFromGeoJSON(feature->>'geometry'),4326),25832)
FROM (SELECT json_array_elements(geojson->'features') AS feature FROM t) data;

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08-04 12:19
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