postgresql - 在 PostgreSQL/PostGIS 中生成饼状楔形(几何图形)的 ID

Question

我有一个查询，它在点层周围 50 米的圆圈(缓冲区)中生成 12 个部分(饼状楔形)。

With buffer as(
SELECT gid as pt_id, (ST_DumpPoints(ST_Buffer(geom,50,3))).geom as geom
FROM my_point_table group by gid, geom
UNION ALL 
SELECT gid as pt_id, geom FROM my_point_table
) 
SELECT gid, (ST_Dump(ST_DelaunayTriangles(ST_Collect(geom),0, 0))).geom geom
FROM buffer
GROUP BY pt_id

我想为这些部分分配 ID，如下所示:

我们将非常感谢有关如何执行此操作的建议。

Answer 1

你可以尝试这样的事情

With my_point_table as (
    select 1 as gid, 'POINT(0 0)'::geometry as geom
    union
    select 2 as gid, 'POINT(1 1)'::geometry as geom
), buffer as(
    SELECT gid as pt_id, (ST_DumpPoints(ST_Buffer(geom,50,3))).geom as geom
    FROM my_point_table group by gid, geom
    UNION ALL 
    SELECT gid as pt_id, geom FROM my_point_table
) , tr as (
    SELECT pt_id, (ST_Dump(ST_DelaunayTriangles(ST_Collect(geom),0, 0))).geom geom
    FROM buffer
    GROUP BY pt_id
)
select row_number() OVER (partition by pt_id), pt_id, geom from tr

第一部分是模拟您的“my_point_table”表。

row_number() OVER(按 pt_id 分区) 是为每个功能生成序列号的原因。