v4.16.2
Bugfixes
SQLite migration fix
This release fixes a critical issue in the SQLite migration, that causes deleting devices from the device table. (#825).
Context: SQLite has limited support for ALTER TABLE queries, therefore it is often needed to re-create the table with the updated schema, copy over the data and remove the old table. In this specific migration, the device_profile table is re-created to drop the NOT NULL constraint on the tenant_id column to make it possible to store both "global" and tenant-owned device profiles. To avoid that this triggers the deletion of data with a foreign-key constraint to this table, the re-create, copy, delete and rename process was between:
pragma foreign_keys = 0;
-- create, copy, delete, rename queries
pragma foreign_keys = 1;
This works fine when executed outside the context of an SQLite transaction (which was tested), but fails when executed within a transaction (when executed through diesel), as per SQLite documentation: This pragma is a no-op within a transaction.
This is fixed by disabling the foreign_keys PRAGMA before diesel starts the transaction for executing migrations.