mirsal/capsul-flask
0
0
Fork 0
forked from 3wordchant/capsul-flask
Code Issues Pull Requests Projects Releases Wiki Activity

correctly handle when the desiredSchemaVersion < schemaVersion

Browse Source
This commit is contained in:
forest
2020-05-09 19:22:25 -05:00
parent 4a1924587c
commit 119d4a0052
2 changed files with 12 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
README.md
View File

@ -7,10 +7,12 @@ Python Flask web application for capsul.org
capsulflask has a concept of a schema version. When the application starts, it will query the database for a table named
`schemaversion` that has one row and one column (`version`). If the `version` it finds is not equal to the `desiredSchemaVersion` variable set in `db.py`, it will run migration scripts from the `schema_migrations` folder one by one until the `schemaversion` table shows the correct version.
For example, the script named `02_up_xyz.sql` should contain code that migrates the database in a reverse-able fashion from schema version 1 to schema version 2. Likewise, the script `02_down_xyz.sql` should contain code that migrates from schema version 2 back to schema version 1.
For example, the script named `02_up_xyz.sql` should contain code that migrates the database from schema version 1 to schema version 2. Likewise, the script `02_down_xyz.sql` should contain code that migrates from schema version 2 back to schema version 1.
**IMPORTANT: if you need to make changes to the schema, make a NEW schema version. DO NOT EDIT the existing schema versions.**
In general, for safety, schema version upgrades should not delete data. Schema version downgrades will simply throw an error and exit for now.
## how to run locally
Ensure you have the pre-requisites for the psycopg2 Postgres database adapter package