How to sum values of points inside polygons?

Question

I have a polygon layer of territory and point layer with values from measurements. I must to add sum values from points layer to polygon layer . How to do this in PostGIS?

Supplemented:

Point layer is:

id|name   |value
1 |first  |547051
2 |second |539949
3 |third  |539864
4 |fourth |539724
5 |fifth  |500208

Pattern layer:

and result must be

id|name|sum
55|I5  |1619037
61|H7  |1047259

Answer 1

Edit: field names corresponding to the questions field name

SELECT
polygons.id
, polygons.name
, coalesce(sum(points.value),0) AS sum
FROM polygons  
    LEFT JOIN points 
    ON ST_Intersects(polygons.geom, points.geom) 
GROUP BY polygons.id;

Then you will get also the polygons without points represented with 0 as sum_value

HTH

Nicklas