CRUD operations such as delete, add, select work quite correctly, but updates do not update anything in the database at all. I’m new to all this.
I am attaching the available code:
@Entity

@Entity(
    tableName = "book",
    foreignKeys = [
        ForeignKey(
            entity = User::class,
            parentColumns = ["user_id"],
            childColumns = ["user_id"],
            onDelete = ForeignKey.NO_ACTION,
            onUpdate = ForeignKey.NO_ACTION
        )
    ]
)
data class Books(
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "book_id")
    val bookId: Int = 0,

    @ColumnInfo(name = "user_id")
    val userId: Int? = null,

    @ColumnInfo(name = "image_url")
    val imageUrl: String? = null,

    @ColumnInfo(name = "title")
    val title: String,

    @ColumnInfo(name = "author")
    val author: String? = null,

    @ColumnInfo(name = "genre")
    val genre: String? = null,

    @ColumnInfo(name = "description")
    val description: String? = null,

    @ColumnInfo(name = "status")
    val status: String? = null,

    @ColumnInfo(name = "rating")
    val rating: Double? = null,

    @ColumnInfo(name = "creation_date")
    val creationDate: Long = System.currentTimeMillis()
)

@Dao

@Update
suspend fun updateBook(book: Books)

@Database

@Database(entities = [User::class, Books::class, Chapters::class], version = 1)
abstract class AppDatabase : RoomDatabase() {
    abstract fun userDao(): UserDao
    abstract fun booksDao(): BooksDao
    abstract fun chaptersDao(): ChaptersDao

    companion object {
        @Volatile
        private var INSTANCE: AppDatabase? = null
        private val LOCK = Any()

        fun getDatabase(context: Context): AppDatabase {
            return INSTANCE ?: synchronized(this) {
                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    AppDatabase::class.java,
                    "app_database"
                ).build()
                INSTANCE = instance
                instance
            }
        }
        operator fun invoke(context: Context) = INSTANCE ?:
        synchronized(LOCK) {
            INSTANCE ?:
            createDatabase(context).also {
                INSTANCE = it
            }
        }

        private fun createDatabase(context: Context) =
            Room.databaseBuilder(
                context.applicationContext,
                AppDatabase::class.java,
                "app_database"
            ).build()
    }
}

Repo

suspend fun updateBooks(books: Books) = db.booksDao().updateBook(books)

ViewModel

fun updateBooks(books: Books) =
        viewModelScope.launch {
            booksRepository.updateBooks(books)
        }

Navigator

composable("change_book/{bookId}",
                    arguments = listOf(navArgument("bookId") {type = NavType.IntType})
                ) {backStackEntry ->
                    backStackEntry.arguments?.getInt("bookId")
                        ?.let { ChangeBook(navController, database, userViewModel, it, updateBooks = { booksViewModel.updateBooks(it) }) }
                }

Composable fun ChangeBook

val books = currentBooks?.let {
                            Books(
                                it.bookId,
                                imageUrl = updatedImage,
                                title = updatedTitle,
                                author = updatedAuthor,
                                genre = updatedGenre,
                                description = updatedDescription
                            )
                        }
                        if (books != null) {
                            updateBooks(books)
                        }

Everything is recorded successfully in the updateImage data and so on (the data in them is correct)

I changed @update to @query.