如何从以下 json 数组类型创建线串几何？

Question

I want to create a LineString geometry with sql statements in postgresql :

'LINESTRING(11.617730473115067 48.19782098770711, ..., ..., 11.618709999927699 48.19985004114398)'

from the following JSON Code :

{ "type": [ "LineString", "LineString" ], "coordinates": [ [ 11.617730473115067, 48.19782098770711 ], [ 11.617959999927661, 48.19828004114453 ], [ 11.617999999927662, 48.1983600411445 ], [ 11.618139999927674, 48.19867004114437 ], [ 11.61840999992768, 48.19925004114419 ], [ 11.618709999927699, 48.19985004114398 ] ] }

How can i split this JSON Array und concatante to the LineString Text.

Answer 1

You can try this :

SELECT 'LINESTRING(' || string_agg(e.elt->>0 || ',' || e.elt->>1, ',' ORDER BY e.id) || ')'
  FROM json_array_elements(your_json_code->'coordinates') WITH ORDINALITY AS e(elt, id)

This query builds the LINESTRING() with the elements in the order of the json array associated to the key 'coordinates'