[postgis-users] Automatically updating postgis from a directory of shapefiles

[Mark Volz]

Hello

I would like to set up an windows batch file that will automatically update PostGIS from a directory of shapefiles.  I have a couple potential code samples, and would appreciate comments.   Thanks

Example 1  - This code will create new tables in postgis from tables, however it doesn't seem to replace existing tables with existing shapefiles: 
for %%f in (*.shp) do shp2pgsql -c -I -s 103749 -W LATIN1 %%f %%~nf > %%~nf.sql
for %%f in (*.sql) do psql -p 5432 -w -U postgres --dbname postgis20 -f %%f

Example 2 - This code will replace existing tables, however it doesn't seem to create new tables.
for %%f in (*.shp) do shp2pgsql -d -I -s 103749 -W LATIN1 %%f %%~nf > %%~nf.sql
for %%f in (*.sql) do psql -p 5432 -w -U postgres --dbname postgis20 -f %%f

Example 3 - I also came across this code as well that will delete all the tables in a database,  which then I could turn around and use shp2pgsql with the -c option.  However I don't want it to take down the spatial reference table:
psql  -U postgres -t -d postgis20 -c "SELECT 'DROP TABLE ' || n.nspname || '.' || c.relname || ' CASCADE;' FROM pg_catalog.pg_class AS c LEFT JOIN pg_catalog.pg_namespace AS n ON n.oid = c.relnamespace WHERE relkind = 'r' AND n.nspname NOT IN ('pg_catalog', 'pg_toast') AND pg_catalog.pg_table_is_visible(c.oid)" >/tmp/droptables
psql  -d postgis20 -f /tmp/droptables

Questions:
1)  Is there a way to protect the spatial reference table so that it would drop when using psql?
2)  Are my Assumptions about the -c and -d flag correct?   Where -c will work only if the table is new, and -d will work only if the table already exists?
3)  Does anyone have any automatic update scripts?  

Thank You

Mark Volz
GIS Specialist