Postgres拆分LineStrings并转换 [英] Postgres split LineStrings and convert

问题描述

我的问题是如何在PL/pgSQL中构建一个函数来做到这一点:

my question is how to build a function in PL/pgSQL to do this :

我有很多这样的线串.

Linestring((3.584731 60.739211,3.590472 60.738030,3.592740 60.736220))

我需要将每个Linestring拆分为一个Substring，然后再次将其拆分为2个坐标.

I need to split every Linestring in a Substring and split it up again in 2 coordinates like this.

3.584731 60.739211  
x1            y1      

3.590472 60.738030 
x2            y2     


3.592740 60.736220
x3              y3

以此类推. 保存答案并将其转换为双精度，以便我可以计算出分数.

And so on with the other points. Save the answers and converting into a double so I can calculate with the points.

推荐答案

使用 ST_DumpPoints :

SELECT ST_X(d.geom), ST_Y(d.geom)
FROM ST_DumpPoints(
    'Linestring(3.584731 60.739211,3.590472 60.738030,3.592740 60.736220)') AS d;

   st_x   |   st_y    
----------+-----------
 3.584731 | 60.739211
 3.590472 |  60.73803
  3.59274 |  60.73622
(3 rows)

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