[postgis-users] Update

[Bob Pawley]

Is there a way of updating an existing column using ST_Translate.

When I try it I get error messages.

I could do it with an insert -  create table, insert, update then drop 
table - but it would be nice if it was more straightforward.

Following is my function.

Bob

 Update p_id.processes
 set arrow_the_geom = Select st_transform (graphics.utilities_dgm.the_geom,

 st_x (st_centroid(p_id.p_id.the_geom)) -
 st_x (st_centroid (graphics.utilities_dgm.the_geom)),
 st_y (st_centroid(p_id.p_id.the_geom))-
 st_y (st_centroid (graphics.utilities_dgm.the_geom)))
 From graphics.utilities_dgm, p_id.p_id
 where graphics.utilities_dgm.utilities_description = 'Arrow_Flow_Direction'
 and graphics.utilities_dgm.orientation = p_id.processes.orient;