我在gis.stackexchange上问过这个问题(但是因为我的实际问题似乎比GIS更多的数据库问题,所以我在这里尝试我的运气)。这里是关于gis.stackexchange的问题:https://gis.stackexchange.com/questions/256535/postgis-2-3-splitting-multiline-by-pointsPostGIS 2.3通过点划分线
我有一个触发器,当我插入一个新行时插入一个循环插入我的表中的分离行集,但由于某种原因,我没有得到想要的结果因为在这个例子中,我只能得到三条中的两条。我做错了什么?
这里谈到的触发功能的代码:
CREATE OR REPLACE FUNCTION public.split_cable()
RETURNS trigger AS
$BODY$
DECLARE compte integer;
DECLARE i integer := 2;
BEGIN
compte = (SELECT count(*) FROM boite WHERE st_intersects(boite.geom, new.geom));
WHILE i < compte LOOP
WITH brs AS (SELECT row_number() over(), boite.geom FROM boite, cable2
WHERE st_intersects(boite.geom, new.geom)
-- here the ORDER BY serve to get the "boite" objects in a specific order
ORDER BY st_linelocatepoint(st_linemerge(new.geom),boite.geom)),
brs2 AS (SELECT st_union(geom) AS geom FROM brs),
cables AS (SELECT (st_dump(st_split(new.geom, brs2.geom))).geom FROM brs2)
INSERT INTO cable2 (geom) VALUES (
SELECT st_multi(cables.geom) FROM cables WHERE st_startpoint(geom) = (SELECT geom FROM brs WHERE brs.row_number = i));
i = i + 1;
END LOOP;
new.geom = (WITH brs AS (SELECT row_number() over(), boite.geom FROM boite, cable2
WHERE st_intersects(boite.geom, new.geom)
ORDER BY st_linelocatepoint(st_linemerge(new.geom),boite.geom)),
brs2 AS (SELECT st_union(geom) as geom from brs),
cables AS (SELECT (st_dump(st_split(new.geom, brs2.geom))).geom FROM brs2)
SELECT st_multi(cables.geom) FROM cables WHERE st_startpoint(geom) = (SELECT geom FROM brs WHERE brs.row_number = 1));
RETURN new;
END
$BODY$
LANGUAGE plpgsql;
在你的例子中'compte'的初始值是什么? – MiguelKVidal
@MiguelKVidal它可以是任何的,但总是至少为2.举个例子,假设它是3,换句话说,就是我应该在第一行的两行中分割结尾的情况。 –
尝试在插入新值之前输出'compte'(在'while'之前)和'SELECT'的值。这将有助于更好地理解发生的事情。 – MiguelKVidal