android - Kotlin：刚从 roomdatabase 取回第一个参数

Question

我的代码有问题，我无法解决。让我简要介绍一下我将要做什么：我在 ChooseFragment 中有一个地址，并且有一个用于编辑地址的编辑按钮。好的，到目前为止很好。编辑单击是将新地址传递给 DatabaseRoom 并且地址文本将被更改。但这只是第一次发生。第二次地址没变！！. 我知道插入方法有效并将新数据发送到数据库室，但是当我想用我的查询（SELECT * FROM ...）获取它时，只显示第一个参数而不用新值替换。我的代码有什么问题？

这是我的桌子：

@Entity (tableName = "addresstable")
data class AddressTb(

    @PrimaryKey(autoGenerate = true)```
    val id : Int? ,
    var address: String)```

这是我的数据库：

@Database(entities = [RoomTables::class , AddressTb::class], version = 1, exportSchema = false)


abstract class DataBaseRoom : RoomDatabase() {

    abstract fun GetDao(): DaoCart


    companion object {
        @Volatile
        private var instance: DataBaseRoom? = null

        private val lock = Any()

        operator fun invoke(context: Context) = instance
            ?: synchronized(lock) {
                instance
                    ?: makeDatabase(
                        context
                    ).also {
                        instance = it
                    }
            }

        private fun makeDatabase(context: Context) = Room.databaseBuilder(
            context.applicationContext,
            DataBaseRoom::class.java,
            "name"
        ).build()
    }

}```
this is my Dao : 
```//address table dao

        @Query("SELECT * FROM addresstable")
        fun getalladress () : LiveData<AddressTb>


        @Insert(onConflict = OnConflictStrategy.REPLACE)
        suspend fun insertaddress (model : AddressTb)


        @Query("DELETE FROM addresstable")
       suspend fun deleteaddress ()

这是我的存储库：

    fun getalladdress() = db.GetDao().getalladress()

    suspend fun deleteaddress() = db.GetDao().deleteaddress()

    suspend fun insertaddress(model : AddressTb) = db.GetDao().insertaddress(model)

这是我的视图模型：

    fun getaddress() = repository.getalladdress()


    fun deleteaddres() = CoroutineScope(Dispatchers.Default).launch {


        repository.deleteaddress()

    }


    fun insertaddress(model : AddressTb) = CoroutineScope(Dispatchers.Default).launch {


        repository.insertaddress(model)

这是我获取新插入的片段：

class ChosseAddress : Fragment() {


    lateinit var viewModelRoom: ViewModelRoom

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {


        val vl = inflater.inflate(R.layout.choose_address_layout, container, false)


        val database = DataBaseRoom(requireContext())
        val repository = RepositoryCart(database)
        val factoryRoom = FactoryRoom(repository)


        viewModelRoom =
            ViewModelProvider(ViewModelStoreOwner { ViewModelStore() }, factoryRoom).get(
                ViewModelRoom::class.java
            )
        viewModelRoom.getaddress().observe(viewLifecycleOwner, Observer {


            try {

                vl.txt_address.text = it.address


            } catch (ex: Exception) {
                null
            }

        })



        val animsec: Animation =
            AnimationUtils.loadAnimation(vl.context, R.anim.anim_for_btn_zoom_out)

        vl.button_back_choose_address.setOnClickListener {

            it.startAnimation(animsec)


            childFragmentManager.beginTransaction()
                .replace(R.id.choose_address_container, HamburgerFragment())
                .commit()

        }

        vl.edit_address.setOnClickListener {


            val mycustomview =
                LayoutInflater.from(context).inflate(R.layout.alertfialog_costume, null)
            val dialogtext = LayoutInflater.from(context).inflate(R.layout.edit_alert_txt, null)

            val mBuilder = AlertDialog.Builder(context)
                .setView(mycustomview)
                .setCustomTitle(dialogtext)
            val show = mBuilder.show()

            mycustomview.edit_manually.setOnClickListener {

                show.dismiss()
                childFragmentManager.beginTransaction()
                    .replace(R.id.choose_address_container, ManuallyAddressFragment())
                    .commit()


            }


        }



        return vl


    }


}```

这是我将数据插入数据库的地方：

class ManuallyAddressFragment : Fragment() {

    lateinit var viewmodel: ViewModelRoom

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

        val layoutview = inflater.inflate(R.layout.manually_address_fragment, container, false)

        val database = DataBaseRoom(layoutview.context)
        val repos = RepositoryCart(database)
        val factory = FactoryRoom(repos)

        viewmodel = ViewModelProvider(ViewModelStoreOwner { viewModelStore },
            factory).get(ViewModelRoom::class.java)


        val btncancle: Button = layoutview.btn_cancle
        val btnsubmit: Button = layoutview.btn_submit_address


        btnsubmit.setOnClickListener {

            val edittext = layoutview.edit_address_manually

            if (edittext.text.toString().isEmpty()) {

                Toast.makeText(context, R.string.submit_btn, Toast.LENGTH_SHORT).show()
            } else {


               val  insert = (AddressTb( null , edittext.text.toString()))
                viewmodel.insertaddress(insert)
                childFragmentManager.beginTransaction()
                    .setCustomAnimations(
                        R.anim.anim_fragment_manually,
                        R.anim.anim_fragment_chooseaddress
                    )
                    .replace(R.id.manually_container, ChosseAddress())
                    .commit()
                Toast.makeText(context, "آدرس شما با موفقیت ثبت شد", Toast.LENGTH_SHORT).show()


            }


        }



        btncancle.setOnClickListener {

            childFragmentManager.beginTransaction()
                .setCustomAnimations(
                    R.anim.anim_fragment_manually,
                    R.anim.anim_fragment_chooseaddress
                )
                .replace(R.id.manually_container, ChosseAddress())
                .commit()

        }



        return layoutview


    }
}```

我试过所以事情也使用更新方法，但数据库只返回第一个参数，我想要新的插入值......

标签： androidkotlininsertfragmentandroid-room

Answer 1

对于初学者，如果您获得所有地址，它应该如下所示：

    @Query("SELECT * FROM addresstable")
    fun getalladress () : LiveData<List<AddressTb>>

要选择单个地址，请使用以下内容：

@Query("SELECT * FROM addresstable WHERE id= :id")
fun findAddressById(id: Long) : AddressTb