Persisting Database States (Postgres)
Persisting Database States (PostgreSQL)
To persist a PostgreSQL database for a learner we will need to create a presave script and a startup script. The presave script will dump the database to a file each time the learner's environment saves. The startup script will load the database from that file. While authoring content we can use the same techniques to create a starting database for the content.
Setting up Persistence for the Learner's Environment
- 1.Create a new content and select the Postgres stack.
- 2.Select Interface from the left sidebar
- 1.Under Tabs Enabled toggle Enable SQL Results Viewer
- 2.Scroll down and change the database type to PostgreSQL
- 3.Type in the name of the database you will be using in this content
- 3.Select Settings in the left sidebar and scroll down
- 1.Add a Presave Script to dump the database to a file whenever the learner environment is saved:
pg_dump {{database}} > ~/workspace/.postgres.sql; - 2.Add a Startup Script to load the database from the database dump:
psql {{database}} < ~/workspace/.postgres.sql;
Creating a Starting Database for the Content
When authoring content, after creating a database and adding any tables and values that you want the learner to start with, you can run the
pg_dump command in a terminal tab (pg_dump {{database}} > ~/workspace/.postgres.sql;) to create a backup. Click Save in the top right corner of the window and the current database state will be restored by the startup script the first time a learner loads the content.