[GRASS-user] python db.execute Unable to open Database

[Phillip Allen]

Hi,

I am writing a short python script to create a PostGIS table, loop through
a csv file, run a series of grass commands, then save the final vector
polygons to the PostGIS table.  All of the PostGIS commands were being
issued by the db.execute.

In the code below I got the message:
ERROR: Unable to open database <host=localhost,dbname=ss_basin_test>

As seen in the 30th line I tried to send user & password along with the
database info but that gave an error as well. When I tried to run db.login
it said I had to use the "overwrite" flag.  If I overwrite the login info
this script I will have to reset it when I am done and I am not sure how to
do that.

How do I connect to the db with db.execute and send the user/password
information?
The first half of my code is below.

thanks,

Phil



# IMPORT CSV & LOOP THROUGH COORDINATES FOR r.water.outlet
import os
import sys

#set up GRASS environment variables
sys.path.append(os.path.join(os.environ['GISBASE'], 'etc', 'python'))
import grass.script as g
import grass.script.setup as gsetup
gisbase = os.environ['GISBASE']

gisdb = 'E:\DEM_12_5\grassdata'
location = 'dem_12_5'
mapset = 'PERMANENT'

#     first join the new snap table's cat column to the original attribute
table
# v.out.ascii input=th_ss_aem_snap_r5 at PERMANENT type=point
output=C:\data\th_ss_aem_snap_r5.csv columns=COD_MUESTR format=point
separator=comma precision=20
txtfile = 'c:/data/th_ss_aem_snap_r5.csv'
txtfileWKT = 'c:/data/th_ss_aem_snap_r5_WKT.txt'
pgsrid = '32618'

pg_user = 'postgres'
pg_user_pwd = 'xxxx'
pg_schema = 'basin'
pg_tbl_name = 'samp_basin'
pg_host = 'localhost'
pg_dbname = 'ss_basin_test'

txt_pg_tbl_create = 'CREATE TABLE ' + pg_tbl_name + ' (x double precision,
y double precision, samp_id character varying(254) PRIMARY KEY, geom
geometry(POLYGON, ' + pgsrid + ') )'

#txt_pg_db = 'host=' + pg_host + ',dbname=' + pg_dbname + ',user=' +
pg_user + ',password=' + pg_user_pwd
txt_pg_db = 'host=' + pg_host + ',dbname=' + pg_dbname

gsetup.init(gisbase, gisdb, location, mapset)

# Create PostGIS Polygon Table
# g.run_command('db.login', driver='pg', user=pg_user, password=pg_user_pwd
)
g.run_command('db.execute', sql=txt_pg_tbl_create , driver='pg',
database=txt_pg_db, schema=pg_schema)
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