室:使用@Transaction时收到错误 [英] Room: Receiving error when using @Transaction

问题描述

我在DAO类中有一个以@Transaction注释的方法，这会导致以下错误:

I'm have a method annotated with @Transaction in my DAO class, which is causing the following error:

DAO方法只能使用以下一项进行注释:插入，删除，查询，更新

A DAO method can be annotated with only one of the following:Insert,Delete,Query,Update

这是我的课程:

@Dao interface Dao {

    @Insert(onConflict = REPLACE) fun insertList(chacaras: List<String>)

    @Query("SELECT * FROM chacara WHERE cityId = :cityId")
    fun getListOfCity(cityId: String): LiveData<List<String>>

    @Delete fun deleteList(chacaraList: List<String>)

    @Transaction
    fun updateList(list: List<String>){
        deleteList(list)
        insertList(list)
    }

}

当我删除使用@Transaction注释的方法时，它将正常编译. 反正有解决此问题的方法吗?

When I remove the method annotated with @Transaction it compiles normally. Is there anyway to fix this?

推荐答案

根据交易文档

将抽象Dao类中的方法标记为事务处理方法.

Marks a method in an abstract Dao class as a transaction method.

将您的班级更改为:

@Dao abstract class Dao {

    @Insert(onConflict = REPLACE) abstract fun insertList(chacaras: List<String>)

    @Query("SELECT * FROM chacara WHERE cityId = :cityId")
    abstract fun getListOfCity(cityId: String): LiveData<List<String>>

    @Delete abstract fun deleteList(chacaraList: List<String>)

    @Transaction
    open fun updateList(list: List<String>){
        deleteList(list)
        insertList(list)
    }

}

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