Room 数据库 自动迁移，无法成功

Question

Room 数据库使用方面

最近看google 官方的room数据库自动迁移的文档。写demo验证，一直无法验证成功.

我尝试从数据库 version 3 升级到 version 4.升级操作是更改User表名称为 appUser。

同时将UserDao里面定义的查询语句从from user，调整为from appUser。将@Entity（tablename=”user“） 替换为 @Entity（tablename=”appuser“）

@Database(
    entities = [User::class, ClassRoom::class], version = 4, autoMigrations = [
        AutoMigration(from = 3, to = 4,spec = AppDatabase.RenameMigration::class)
    ], exportSchema = true
)
abstract class AppDatabase : RoomDatabase() {
    abstract fun userDao(): UserDao
    abstract fun classRoomDao(): ClassRoomDao
    private val mIsDatabaseCreated = MutableLiveData<Boolean>()

     @RenameTable(fromTableName = "User", toTableName = "appuser")
     class RenameMigration : AutoMigrationSpec

}

运行结果及报错内容

/Users/yangweichao/application/jetPack/Room/app/build/tmp/kapt3/stubs/debug/com/kuaidao/jetpackroom/db/AppDatabase.java:7: 错误: AutoMigration Failure in 'RenameMigration': The table renamed from 'User' to 'appuser' is not found in the new version of the database.
public abstract class AppDatabase extends androidx.room.RoomDatabase {
                

相关链接

https://developer.android.com/training/data-storage/room/migrating-db-versions