db: defer sqlite foreign keys during migration #454
Merged
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Sqlite provides only limited alter tables capabilities, complex things must be done by creating a new table and migrating the data. Things becomes more complex when other tables references the table being altered.
For doing this the documentation provides a list of steps https://www.sqlite.org/lang_altertable.html#making_other_kinds_of_table_schema_changes The first stable is disabling foreign keys, but this must be done outside a transaction.
This patch adds this to the migration logic: disable foreign keys outside transaction, check foreign keys before committing the transaction and then re enable them outside the transaction.