About

Import GTFS data into a PostgreSQL database. Includes all the constraints in the GTFS spec with some basic tools for dealing with improper data

Requirements

• Postgresql database (10+) with a PostGIS (2.2+) extension

Links

• GTFS (General Transit Feed Specification)
• Transitfeeds (index and archive of GTFS data sets)
• Transit.land A community-edited service with an achive of GTFS.

Initial import

This importer uses a Makefile to organize a series of SQL commands. The file src/load.sh is a shell script that does the heavy lifting of loading the contents of a GTFS zip file into a PostgreSQL database.

Before importing data, set up database and make sure to provide relevant variables:

export PGDATABASE=mydbname
export PGUSER=mydbuser
export PGHOST=mydbhost
export PGPORT=mydbport
make init

This will create the a new schema with the necessary tables, as well as useful indices and foreign keys.

Schema

By default, your GTFS data will be loaded into a schema named gtfs. You can always rename it when you're done. Setting the SCHEMA variable when running make tasks will also address a different schema

Connecting to the database

Use the standard Postgres environment variables to specify your connection parameters. For example:

export PGDATABASE=mydbname PGHOST=example.com PGUSER=username
make load GTFS=gtfs.zip

Importing

To import the GTFS dataset in file named gtfs.zip. Note that we first drop foreign key and not null constraints. This is necessary because the tables will be loaded in parallel (-j option) in arbitrary order:

make drop_constraints
make -j load GTFS=gtfs.zip
make add_constraints

Feed indexes

GTFS data is regularly updated, and it's reasonable to want to include multiple iterations in the same database. This tool includes a feed_index column in each table. This index is part of the primary key of each table.

Extra columns

The loading script checks for extra columns in a GTFS table and adds them to database as text columns. You may wish to alter or remove these columns.

Big datasets

For large feeds, you may find that loading is faster without indices. Don't forget to add them back, or your queries will be very slow:

make drop_indices drop_constraints
make load GTFS=gtfs.zip
make add_indices add_constraints

Troubleshooting common errors in GTFS data

Most GTFS data has errors in it, so you may encounter an error when trying to add constraints back. Common errors include missing service_ids.

The check task will run the scripts in tests/validity, which perform several queries looking for rows that violate foreign key constraints and bad geometries in the shapes table. These tests require prove, a very common perl testing program and pgTAP, a Postgresql testing suite. Install it in a new tap schema with:

wget https://api.pgxn.org/dist/pgtap/1.2.0/pgtap-1.2.0.zip
unzip pgtap-1.2.0.zip
make -C pgtap-1.2.0 sql/pgtap.sql
PGOPTIONS=--search_path=tap,public psql -c "CREATE SCHEMA tap" -f pgtap-1.2.0/sql/pgtap.sql

Then run the check task, giving the index of the feed to check:

make check FEED_INDEX=1

The resulting report will tell you which tables have constraint violations, and what the errors are. You may wish to manually add missing values to your tables. It also checks if all tables are populated (some optional tables may not be).

If you don't have prove available, try another TAP consumer. Failing that, you can run the tests with:

find tests -name '*.sql' -print -exec psql -Aqt -v schema=gtfs -f {} \;

Null data

ERROR:  null value in column "example_id" violates not-null constraint

This might occur if an "id" column (e.g. route_id) is improperly empty. As a workaround, you can drop NOT NULL constraints from the database and reload the data:

make drop_notnull
make load GTFS=example.zip

Then edit the database to add a non-empty value and recreate the not-null constraints (make add_notnull).

License

Released under the MIT (X11) license. See LICENSE in this directory.