[GRASSLIST:3456] Sites & v.surf.idw in G57 - attr in Postgres

GRASS GRASS user
1

Hello, This is possibly a dumb question, but I can't figure out what to do based on docs, and other postings.

I am trying to use v.surf.idw to create a DEM in G57. My sites/vector file was imported from ESRI coverages using v.in.ogr. The elevation values are stored in a Postgres table. How can I get v.surf.idw to see those elevations? I get errors like:

decimal field 1 not present in sites file

I doesn't matter what I enter for the field, keep getting a similar error.

So what do I need to do? Create a temporary vector file with my elevations stored within? How do I do that?

Thanks
Craig