如何在房间数据库kotlin中保存号码

我想创建一个简单的财务报告应用程序

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由于期初余额、库存购买、其他费用、销售和银行业务都是双倍数字，我想使用room数据库、jetpack组件

您不能问此类问题，但请看此示例（使用roomDB的最简单方法）

首先，您需要定义数据库类

@Database(entities = [CompaniesModel::class,  UserPoint::class], version = 15) //here is the models which will have the structure of your database  
abstract class DataBase : RoomDatabase() {

/**
 * define companies dao to make some quires
 */
abstract fun homeDao(): HomeDao
abstract fun companiesDao(): CompaniesListDao

companion object {
    @Volatile
    private var databaseInstance: DataBase? = null

    fun getDatabaseInstance(mContext: Context): DataBase =
        databaseInstance ?: synchronized(this) {
            databaseInstance ?: buildDatabaseInstance(mContext).also {
                databaseInstance = it
            }
        }

    private fun buildDatabaseInstance(mContext: Context) =
        Room.databaseBuilder(mContext, DataBase::class.java, "crm")
            .fallbackToDestructiveMigration()
            .allowMainThreadQueries()
            .build()
    }
}

以及包含数据库结构的模型

@Entity(tableName = "companiesModel")
data class CompaniesModel(

@PrimaryKey
@ColumnInfo(name = "id")
@SerializedName("id")
var id: Int,
@ColumnInfo(name = "name")
@SerializedName("name")
var name: String,
@ColumnInfo(name = "image")
@SerializedName("image")
var image: String

)

还有那把有你所有疑问的刀

@Dao
interface CompaniesListDao {
/**
 * this fun to insert data in room db after fetch data from server
 */
@Insert(onConflict = OnConflictStrategy.REPLACE)
fun insertCompanies(contactModel: List<CompaniesModel>)

/**
 * this fun to get data from room db to make some caching in app
 */
@Query("SELECT * FROM companiesModel")
fun getCompaniesList(): List<CompaniesModel>

/**
 * this fun to clear companies list from room db
 */
@Query("DELETE FROM companiesModel")
fun clearCompaniesList()

@Update
fun update(contactModel: List<CompaniesModel>)
}

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请具体回答你的问题。如果您不确定从哪里开始，请尝试在线提供的教程或示例代码，并回答您特别面临的任何问题。

DataBase.getDatabaseInstance(App.instance).companiesDao().something