Question

我正在尝试编写一个PostGIS最近邻居查询，其中选择了一组坐标，并确定了与最接近的泛滥多边形的距离。然后，我想将距离分类为“外部”，“关闭”和“关闭”。或者＆＃39; INSIDE＆＃39;：

WITH 
  point_loc (geom) AS ( 
    SELECT ST_SetSRID(ST_MakePoint(531673.0, 180848.2),27700) ),
  distances (gid, distance) AS (
    SELECT  
      fl.gid,
      ST_Distance(fl.geom, p.geom) AS distance
    FROM
      point_loc p, flooding fl
    WHERE ST_DWithin(p.geom, fl.geom, 400)
  SELECT 
    gid,
    CASE WHEN distance > 300 THEN 'OUTSIDE'
         WHEN distance > 50 AND <= 300 THEN 'CLOSE'
         ELSE 'INSIDE'
    END as flood_result
  FROM distances;

我在最后的SELECT调用中遇到语法错误。谁能看到我做错了什么？

Answer 1

您在第二次CTE上错过了一个右括号。

这一行： WHERE ST_DWithin(p.geom, fl.geom, 400)

应该是： WHERE ST_DWithin(p.geom, fl.geom, 400) )

PostGIS中最近邻搜索出错

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