[postgis-users] spatial joins (geometry collection?)

[Wood Brent]

I plan to join a table of line features with a table of polygons, based on
which lines cross which polygons. This is for a spatial analysis of the line
data by dividing the survey area into small cells to give a raster style
breakdown of the line attributes.

The data will then be queried with a variety of "select <sum/avg/etc> ... group
by cell;" sql to give a wide range of models over the area which can be
displayed as coloured cells or contoured. 

The result, if inserted into a new table, will need to convert the two distinct
geometries into a single geometry collection matching the two geometries (as I
believe you can't have two geometry columns in a table).

I'll need to pre-define the the new table & add the geometry to it, but how do
I write the joining sql to merge the two separate geometries into the new
table?

 Thanks again...

   Brent Wood