Mapping Hacks

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Chapter 8, Building the Geospatial Web

#87 Build a Spatially Indexed Data Store

HACK

This step loads the PostGIS schema and functions into your new database:

#> psql -d tiger -f postgis.sql

You may need to provide the full path to wherever postgis.sql was installed

on your system. One final step is needed to add data to the

spatial_ref_sys

table, which contains metadata about the different spatial projections that

the geometry can be in:

#> psql -d tiger -f spatial_ref_sys.sql

If everything’s working, you should see the last line COMMIT (see also http://

postgis.refractions.net/docs/x83.htm).

Getting Data into PostGIS

A spatial database is no fun without spatially meaningful data. There are

several techniques for getting your information into PostGIS.

Import a shapefile into PostGIS with shp2pgsql. You can use shp2pgsql to import

geospatial data in shapefile format into PostGIS. For example, you might

have a shapefile that contains a set of political boundaries for which you

want to ask, “Which voting area contains this address? Where is the nearest

polling station? What was the voter turnout rate in the last election?”

The shp2pgsql script comes with PostGIS and will convert a shapefile into a

set of insert statements suitable for loading into a PostGIS database. To

import a shapefile, try the following command:

shp2pgsql -c shapefile [database_name.]table_name

The database name is optional. To