Finding nearest line/point from polygon using PostGIS?

Question

I have got the point and the polygon (or line). I have to find the closest coordinate (it can be the "virtual" point on edge) from polygon due to the point.

Do you know how to find out this coordinate?

Answer 1

This should work http://postgis.net/docs/ST_ClosestPoint.html

ST_ClosestPoint — Returns the 2-dimensional point on g1 that is closest to g2. This is the first point of the shortest line.