Method migrate

app/src/main/java/eu/faircode/email/DB.java:773–3148

(final Context context, RoomDatabase.Builder<DB> builder)

    }

    private static RoomDatabase.Builder<DB> migrate(final Context context, RoomDatabase.Builder<DB> builder) {
        // https://www.sqlite.org/lang_altertable.html
        return builder
                .addMigrations(new Migration(1, 2) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `folder` RENAME COLUMN `after` TO `sync_days`");
                        db.execSQL("ALTER TABLE `folder` ADD COLUMN `keep_days` INTEGER NOT NULL DEFAULT 30");
                        db.execSQL("UPDATE `folder` SET keep_days = sync_days");
                    }
                })
                .addMigrations(new Migration(2, 3) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `identity` ADD COLUMN `signature` TEXT");
                        db.execSQL("UPDATE `identity` SET signature =" +
                                " (SELECT account.signature FROM account WHERE account.id = identity.account)");
                    }
                })
                .addMigrations(new Migration(3, 4) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `message` ADD COLUMN `forwarding` INTEGER" +
                                " REFERENCES `message`(`id`) ON UPDATE NO ACTION ON DELETE SET NULL");
                        db.execSQL("CREATE INDEX `index_message_forwarding` ON `message` (`forwarding`)");
                    }
                })
                .addMigrations(new Migration(4, 5) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `account` ADD COLUMN `last_connected` INTEGER");
                        db.execSQL("ALTER TABLE `message` ADD COLUMN `last_attempt` INTEGER");
                    }
                })
                .addMigrations(new Migration(5, 6) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `account` ADD COLUMN `notify` INTEGER NOT NULL DEFAULT 0");
                    }
                })
                .addMigrations(new Migration(6, 7) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `message` ADD COLUMN `answered` INTEGER NOT NULL DEFAULT 0");
                        db.execSQL("ALTER TABLE `message` ADD COLUMN `ui_answered` INTEGER NOT NULL DEFAULT 0");
                    }
                })
                .addMigrations(new Migration(7, 8) {
                    @Override
                    public void migrate(@NonNull SupportSQLiteDatabase db) {
                        logMigration(startVersion, endVersion);
                        db.execSQL("ALTER TABLE `message` ADD COLUMN `keywords` TEXT");