# 5.0 Migration Guide

**Major Changes**

1. Package name is now `com.dbflow5` , which enables bundling multiple versions in the same repo.
   1. **Note:** Using multiple versions of DBFlow on the same DB is not recommended, as it can lead to inconsistent usage on the database in respect to transaction queuing, migrations, or synchronization.
2. Library is now **100%** Kotlin, except generated code. KSP (Kotlin Source Processing) is promising, but will require major updates to support it directly. This means that any `-kotlinextensions` artifacts are not rolled within the library.
3. Library now adds support for **incremental annotation processing.** Please report any issues!
4. New artifacts: `paging`(architecture components Paging),  `coroutines`, `contentprovider`, (splits out `ContentProvider` usage out of main library), `livedata`, `reactive-streams` (RXJava3).
   1. `RXJava`1 and 2 support is dropped given, <https://github.com/ReactiveX/RxJava/tree/2.x> is now in maintenance mode. You simply need to copy paste the `reactive-streams` files you need and then replace the package names back to their RXJava2 equivalent. RXJava 1 is not quite equivalent and not supported.
5. `save()` methods on the `ModelAdapter` classes now use a more efficient `INSERT OR REPLACE` method, rather than check if `exists` manually from the DB before inserting or replacing.
6. `@Database` classes must now be an abstract class that extends `DBFlowDatabase` (or related subclass)
   1. ```
      @Database(version = 1)
      abstract class AppDatabase : DBFlowDatabase()
      ```
7. Removed deprecated `@Database` annotation fields including `name`, `databaseExtension`, and `inMemory`. Use the `DatabaseConfig.Builder` object when initializing DBFlow.
8. The implicit `DatabaseWrapper` that was used in model operations is now required explicit.
9. ```
   // 4.x
   // this would grab the default database from the FlowManager
   model.save()

   // 5.x
   database<AppDatabase> { db -> model.save(db) }
   ```
10. `ModelAdapter.bindToContentValues` and corresponding `ContentValues` generated code is no l longer enabled by default. If you need the methods, set `@Table(generateContentValues = true)`. 1. For `@ContentProvider` object, your db must now extend `ContentProviderDatabase` to supply `ContentValues` methods on the database.
11. Explicitly marking every field in a `@Table` with `@Column` is no longer the default. By default any field in the model class are referenced. To enable the old behavior use `@Table(allFields = false)`
12. Adds `@Fts3` and `@Fts4` annotations. See SQLite docs on [Fts3 and 4.](https://www.sqlite.org/fts3.html)
13. `@ModelView`: gets `orderedCursorLookup`, `assignDefaultValuesFromCursor` , and `createWithDatabase` that were allowed on `@Table` classes.
    1. `@ModelViewQuery` can now be used on a `Property`
14. `@QueryModel`: gets `orderedCursorLookup`, and`assignDefaultValuesFromCursor` that were allowed on `@Table` classes.
15. `IMultiKeyCacheConverter` renamed to `MultiKeyCacheConverter`&#x20;
16. Performing DB operations not in a transaction will throw a new warning in `FlowLog`: `Database Not Running in a Transaction. Performance may be impacted, observability will need manual updates via db.tableObserver.checkForTableUpdates()`
17. `QueryModelAdapter` is deprecated as `RetrievalAdapter` performs all functionality.
18. DBFlowDatabase can now specify a `JournalMode` to support write-ahead logging. **Note**: on higher end devices this will enable `WriteAheadLogging` by default.
19. New `TableObserver` class on a `DBFlowDatabase`. Inspired by Room, this sets up `Trigger` on table changes for observed tables to efficiently track which table changes. This is useful in recomputing queries for `LiveData`, `Flowable` , or `Paging` `DataSource`. Whenever a `Transaction` is run on the DB, upon completing it, we check for any table changes and dispatch that to the active queries that are observed.&#x20;
    1. ```
       (select from MyTable::class ...)
         .toLiveData(db)
         .observe(owner) { r -> }
       ```
20. `AlterTableMigration` supports default values for a column when adding a column.
21. `Index.enable` renamed to `createIfNotExists`, `Index.disable` renamed to `drop`.&#x20;
22. Reduce generated code in tables.&#x20;