[postgis-users] How can I get points of a polygon

[Kevin Neufeld]

Amrita p wrote:
>
>   Hi All,
>
> I want to display all coodinates of a polygon. Is there any function 
> in postgis to get the coordinate of a polygon.
>

In a round-about kind of way.

Use can use ST_ExteriorRing(...) and ST_InteriorRingN(...) to extract 
the lines from the polygon.
Then use ST_PointN(...) to get the points in the LINESTRINGs.
>
>
> Is there any method to split polygon into two or more parts if 
> co-odinates are given...
>

You mean split a polygon given a line that crosses?  Not directly. 
But you can do this:
- extract the lines that make up the polygon (as above)
- add to this your crossing line
- geomunion the lines together.
- polygonize the union-ed set

Cheers,
-- Kevin
>
>
> regards,
> Amrita
>
>