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I have two tables in postgis (pgadmin). In one table there are points and in the other table there are polygons(provinces). The tables are both over the same location (Netherlands). I want to count the points who are in every province and I want to export them to a row in the polygon (maybe a new table). Summarized: I want from every province the points counted in a row.

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Assuming the points and polygons are in the same projection (same SRID):

Add a column to the provinces table to store point counts:

ALTER TABLE provinces ADD COLUMN count_pts int;

Update the column with point counts:

UPDATE provinces SET count_pts = 
(SELECT ct FROM 
    (SELECT gid, count(gid) AS ct FROM
        (SELECT pts.pts_id AS id, provinces.gid AS gid FROM pts,provinces 
        WHERE st_intersects(pts.geom,provinces.geom)) a 
    GROUP BY gid) b
WHERE provinces.gid = b.gid);

Note that if a point fell in multiple polygons (this could be the case if polygons overlapped one another) if would be counted in both polygons.

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