IPasswordsRepository

interface IPasswordsRepository {
    fun getAllPasswords(): Flowable<List<PasswordRepoEntity>>
    fun getPasswordById(passwordId: Long): Single<PasswordRepoEntity>
    fun deletePasswordsByIds(passwordIds: List<Long>): Single<Boolean>
    fun addNewPasswords(passwordRepoEntities: List<PasswordRepoEntity>): Single<Boolean>
    fun updatePasswords(passwordRepoEntities: List<PasswordRepoEntity>): Single<Boolean>
}

PasswordDBEntity

@Entity(tableName = PasswordDBEntity.PASSWORD_TABLE_NAME)
data class PasswordDBEntity(
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = COLUMN_PASSWORD_ID)
    var passwordIdValue: Long?,
    @ColumnInfo(name = COLUMN_PASSWORD_NAME)
    var passwordNameValue: String,
    @ColumnInfo(name = COLUMN_PASSWORD_AVATAR_PATH)
    var passwordAvatarPathValue: String,
    @ColumnInfo(name = COLUMN_PASSWORD_CONTENT)
    var passwordContentValue: String
) : PasswordRepoEntity {

    @Ignore
    constructor(passwordId: Long) : this(passwordId, "", "", "")
    @Ignore
    constructor(passwordName: String, passwordContent: String, avatarPath: String?)
            : this(null, passwordName, avatarPath ?: "", passwordContent)

    companion object {
        const val PASSWORD_TABLE_NAME = "Passwords"

        // column names
        const val COLUMN_PASSWORD_ID = "password_id" // autogenerated primary key
        const val COLUMN_PASSWORD_NAME = "password_name" // password alias
        const val COLUMN_PASSWORD_AVATAR_PATH = "password_avatar_path" // url of password picture
        const val COLUMN_PASSWORD_CONTENT = "password_content" // url of password picture
    }

    override fun getPasswordId(): Long? = passwordIdValue

    override fun getPasswordName(): String = passwordNameValue

    override fun getPasswordAvatarPath(): String = passwordAvatarPathValue

    override fun getPasswordContent(): String = passwordContentValue
}

PasswordRepoEntity

interface PasswordRepoEntity {
    fun getPasswordId(): Long?
    fun getPasswordName(): String
    fun getPasswordAvatarPath(): String
    fun getPasswordContent(): String
}

PasswordsDAO

@Dao
interface PasswordsDAO {

    @Query("SELECT * FROM " + PasswordDBEntity.PASSWORD_TABLE_NAME)
    fun getAllPasswords(): Flowable<List<PasswordDBEntity>>

    ..............
    ..............
    ..............
    ..............
}

PasswordsRepositoryImpl

class PasswordsRepositoryImpl @Inject constructor(
    private val passwordsLocalStore: PSDatabase
) : IPasswordsRepository {

    override fun getAllPasswords(): Flowable<List<PasswordRepoEntity>> =
        passwordsLocalStore.getPasswordsDao()
            .getAllPasswords()
            .subscribeOn(Schedulers.io())
            
            ...............
            ...............
            ...............
            
}