• Table of contents
• Replace the database with a backup
• Exports
  • Database Structure
  • Model Data
  • Single Schema
• Add update trigger for modified field
  • Export database for Windows
• Reset Demo
• Find used but missing places
• Delete orphaned locations
• Import database to Windows
• Recursive Events

Below are some unsorted database related code snippets used in development.

Replace the database with a backup¶

It is possible (for users with the role admin or manager) to make SQL dumps via the backend anytime: admin -> data -> SQL export. Also, every time the database_upgrade.py script, which is used at an upgrade to a new OpenAtlas version, is called before doing database changes. These backups are located at files/export and because the date of creation is included in the filename it is easy to see when they were made. Of course it is good practice to store these SQL backups on another machine too, e.g. in case of a hard disk failure, but this is outside the scope of OpenAtlas.

In case these backups are needed, lets say for example an import went wrong, the workflow on a Debian machine would be as follows. The commands are executed as postgres user and it is assumed the database and user are called openatlas.

• Delete the current database
  

  dropdb openatlas

• Create a new, empty database with the owner openaltas
  

  createdb openatlas -O openatlas

• Import the (unpacked) backup into the new database
  

  psql openatlas < path/to/the/unpacked/backup.sql

Exports¶

Database Structure¶

Export the database structure from the test database (used to avoid specialties in production databases) into install/1_structure.sql

pg_dump -sc --if-exists -n model -n gis -n log -n web -n import openatlas_test > install/1_structure.sql

Model Data¶

pg_dump openatlas --rows-per-insert 10000 -a -t model.cidoc_class -t model.cidoc_class_i18n -t model.cidoc_class_inheritance -t model.property -t model.property_i18n -t model.property_inheritance > install/2_data_model.sql

Single Schema¶

pg_dump -n web openatlas > /tmp/openatlas_web.sql
pg_dump -n model openatlas > /tmp/openatlas_web.sql

Add update trigger for modified field¶

Replace schema.table and execute:

CREATE TRIGGER update_modified BEFORE UPDATE ON schema.table FOR EACH ROW EXECUTE PROCEDURE model.update_modified();

Export database for Windows¶

pg_dump -Fc openatlas > openatlas.dump

to ingest in windows

C:\Program Files\PostgreSQL\12\bin\pg_restore.exe --host "localhost" --port "5432" --username "postgres" --no-password --dbname "openatlas" --clean --verbose "path to dump file" 

Reset Demo¶

/var/lib/postgresql/reset_demo.sh

Find used but missing places¶

e.g. after a case study separation (not sure if this statement is now showing really missing or just needed locations)

SELECT e.id, e.name, e.system_type FROM model.entity e
WHERE e.class_code = 'E53' AND e.system_type = 'place location' AND e.id IN (
   SELECT r.id FROM model.link lr JOIN model.entity r ON lr.range_id = r.id AND lr.property_code IN ('P74', 'OA8', 'OA9', 'P7'))
   AND e.id NOT IN (SELECT range_id FROM model.link WHERE property_code = 'P53');

Delete orphaned locations¶

DELETE FROM model.entity WHERE id IN (
    SELECT id FROM model.entity WHERE system_type = 'place location' AND id NOT IN (
        SELECT e.id FROM model.entity e JOIN model.link l ON e.id = l.range_id AND l.property_code = 'P53' 
        WHERE e.class_code = 'E53' AND e.system_type = 'place location'));

Import database to Windows¶

Make a dump with inserts

pg_dump --attribute-inserts openatlas > openatlas.sql

In the pgadmin tool, select the corresponding database, run the query tool and select the open file option.
Load the provided dump file and execute (F5) it.
Login and adapt user as needed.

Recursive Events¶

To get all child events of a given event the SQL below (replace ROOT_EVENT_ID at bottom). It works but is slow and could be improved.

WITH RECURSIVE tree AS (
  SELECT e.id, ARRAY[]::INTEGER[] AS ancestors
  FROM model.entity e
  WHERE (SELECT s.id FROM model.entity s JOIN model.link l ON s.id = l.range_id AND l.domain_id = e.id AND l.property_id = (SELECT id FROM model.property WHERE code = 'P117')) IS NULL 
  UNION ALL 
  SELECT e.id, tree.ancestors || 
    (SELECT s.id FROM model.entity s JOIN model.link l ON s.id = l.range_id AND l.domain_id = e.id AND l.property_id = (SELECT id FROM model.property WHERE code = 'P117'))
  FROM model.entity e, tree
  WHERE (SELECT s.id FROM model.entity s JOIN model.link l ON s.id = l.range_id AND l.domain_id = e.id AND l.property_id = (SELECT id FROM model.property WHERE code = 'P117')) = tree.id
)
SELECT * FROM tree WHERE ROOT_EVENT_ID = ANY(tree.ancestors);