st_intersects on postgis

Question

I'm trying to write a command to see whether a given point lies within a multipolygon boundary (in this case, a watershed). I have a table of watershed boundaries and another table with the point I'm going to use to see which watershed the point lies in.

Would st_intersects be the correct command to run? (if so, how would I do that?). If not, what would be the best command to use?

I'm new to postgis/postgresql so any help would be greatly appreciated.

Here are what the tables look like:

Table A has point data:

Table H has polygons:

Answer 1

This should do what you're asking:

SELECT a.name, h.name
 FROM a5 a, HUC8 h
 WHERE ST_Intersects(a.the_geom, h.the_geom);