Room-Migration

val MIGRATION_8_9 = object : Migration(8, 9) {
        override fun migrate(database: SupportSQLiteDatabase) {
        
  database.execSQL("CREATE TABLE `savedAlbums_new` (`entityOwnerId` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `id` TEXT NOT NULL, `artwork` TEXT, `artist` TEXT, `description` TEXT, `album_genre` TEXT, `name` TEXT, `presave` INTEGER NOT NULL, `artist_name` TEXT, `label` TEXT, `created` INTEGER NOT NULL, `modified` INTEGER NOT NULL, `releasedate` INTEGER NOT NULL, `entityOwner` TEXT, `uniqueId` TEXT, `indexInQueue` INTEGER NOT NULL default -1, `sharelink` TEXT)")
            database.execSQL("CREATE UNIQUE INDEX `index_savedAlbums_uniqueId` ON `savedAlbums_new` (`uniqueId`)")
            database.execSQL("INSERT INTO `savedAlbums_new` (`id` , `artwork`, `artist` , `description` , `album_genre`, `name` , `presave` , `artist_name`, `label` , `created` , `modified` , `releasedate`, `entityOwner`) select `id` , `artwork`, `artist` , `description` , `album_genre`, `name` , `presave` , `artist_name`, `label` , `created` , `modified` , `releasedate`, `entityOwner` from savedAlbums ")
            database.execSQL(" DROP TABLE savedAlbums ")
            database.execSQL("ALTER TABLE savedAlbums_new RENAME TO savedAlbums")
}

....
....
 Room.databaseBuilder(androidApplication(), xxxDatabase::class.java, "xxxDabase")
            .addMigrations(MIGRATION_8_9)
            .build()

Steps:

1. Create a new table with the new structure
2. Copy the data from the old table into the new table
3. Drop the old table
4. Rename the new table to match the old table