获取随机android.database.sqlite.SQLiteBlobTooBigException

Question

我在我的应用程序中使用 Room 作为单一数据源，因此来自后端的所有内容都保存在我的房间数据库中，然后返回一个 Flowable，每次数据更改时都会触发一个事件。这是我的 PlacesDAO：

    @Dao
abstract class PlacesDao {


    @Query("select * from places where placeId = :id")
    abstract fun getPlace(id: String): Flowable<PlaceVO>

    @Query("select * from places where placeId in (:placesIds) order by distance, placeName ASC")
    abstract fun getPlaces(placesIds: List<String>): Flowable<List<PlaceVO>>


    @Query("select * from places join list_results where Places.placeId = list_results.id order by distance, placeName ASC")
    abstract fun getFilteredPlaces(): Flowable<List<PlaceVO>>



    @Query("select * from places join user_places where Places.placeId = user_places.placeId AND user_places.userId = :userId order by distance, placeName ASC ")
    abstract fun getAllByUser(userId: String) : Flowable<List<PlaceVO>>



    @Insert(onConflict = OnConflictStrategy.REPLACE)
    abstract fun realSavePlaces(places:List<PlaceVO>)



    fun savePlaces(places: List<PlaceVO>){
        Timber.w("PAGELIST - Saving places again!!")
        realSavePlaces(places)
    }

    @Insert(onConflict = OnConflictStrategy.REPLACE)
    abstract fun savePlace(place: PlaceVO)



    @Query("DELETE from places")
    abstract fun deleteAll()

    @Query("select * from places")
    abstract fun getAll(): Single<List<PlaceVO>>




    @Query("select * from places where (experienceId IS NOT NULL) AND (experienceId != '') order by placeName")
    abstract fun getMyPlaces(): Flowable<List<PlaceVO>>

    @Query("update places set distance = :distance and distanceSet = 1 where placeId = :id")
    abstract fun updateDistance(id: String, distance: Float)
}

现在，在我的应用中，有一些操作会触发更改此表中的数据，这会导致我的 UI 接收表中包含的所有项目（大约 3000-5000）。

它并不总是发生（这使得它难以重现），但我会时不时地遇到以下崩溃：

Caused by android.database.sqlite.SQLiteBlobTooBigException: Row too big to fit into CursorWindow requiredPos=1223, totalRows=114
       at android.database.sqlite.SQLiteConnection.nativeExecuteForCursorWindow(SQLiteConnection.java)
       at android.database.sqlite.SQLiteConnection.executeForCursorWindow + 895(SQLiteConnection.java:895)
       at android.database.sqlite.SQLiteSession.executeForCursorWindow + 836(SQLiteSession.java:836)
       at android.database.sqlite.SQLiteQuery.fillWindow + 62(SQLiteQuery.java:62)
       at android.database.sqlite.SQLiteCursor.fillWindow + 157(SQLiteCursor.java:157)
       at android.database.sqlite.SQLiteCursor.onMove + 128(SQLiteCursor.java:128)
       at android.database.AbstractCursor.moveToPosition + 237(AbstractCursor.java:237)
       at android.database.AbstractCursor.moveToNext + 269(AbstractCursor.java:269)
       at com.myapp.android.model.db.dao.PlacesDao_Impl$6.call + 814(PlacesDao_Impl.java:814)
       at com.myapp.android.model.db.dao.PlacesDao_Impl$6.call + 771(PlacesDao_Impl.java:771)
       at io.reactivex.internal.operators.maybe.MaybeFromCallable.subscribeActual + 46(MaybeFromCallable.java:46)
       at io.reactivex.Maybe.subscribe + 4262(Maybe.java:4262)
       at io.reactivex.internal.operators.flowable.FlowableFlatMapMaybe$FlatMapMaybeSubscriber.onNext + 132(FlowableFlatMapMaybe.java:132)
       at io.reactivex.internal.operators.flowable.FlowableObserveOn$ObserveOnSubscriber.runAsync + 407(FlowableObserveOn.java:407)
       at io.reactivex.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.run + 176(FlowableObserveOn.java:176)
       at io.reactivex.internal.schedulers.ExecutorScheduler$ExecutorWorker$BooleanRunnable.run + 260(ExecutorScheduler.java:260)
       at io.reactivex.internal.schedulers.ExecutorScheduler$ExecutorWorker.run + 225(ExecutorScheduler.java:225)
       at java.util.concurrent.ThreadPoolExecutor.runWorker + 1167(ThreadPoolExecutor.java:1167)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run + 641(ThreadPoolExecutor.java:641)
       at java.lang.Thread.run + 764(Thread.java:764)

我只存储文本信息，正如这个类所证明的那样：

@Entity(tableName = "places")
data class PlaceVO(
        @PrimaryKey
        var placeId: String,

        var googleId: String,

        var placeName: String,

        var phoneNumber: String,

        @Embedded
        var primaryCategory: Category?,

        var primaryCategoryTags: List<CategoryTag> = emptyList(),

        var secondaryCategories: List<Category>? = emptyList(),

        var images: List<Image>,

        var website: String,

        var formattedAddress: String? = "",

        var vicinity: String = "",

        var vicinityShort: String = "",

        var city: String? = "",

        var neighbourhood: String?,

        var longitude: Double,

        var latitude: Double,

        var openingHours: List<String>,

        var combinedHighlights: List<HighlightCountWrapper>,
        @Embedded
        var ownExperience: OwnExperience?,

        var otherExperiences: List<Experience>,

        var distance: Float?,

        var distanceSet: Boolean = false,

        var comment: String
) : MarkerPlace {

}

体验课：

@Entity
data class Experience(
        @Json(name="id")
        val experienceId: String,
        @Embedded
        val owner: User,
        val description: String?,
        val highlights: List<Highlight>?,
        val images: List<Image> = emptyList(),
        val createdDate: Date,
        val updatedDate: Date,
        var privacyLevel: AddExperience.Privacy? = null)

一些类型转换器：

@TypeConverter
    fun toHighlightWrapperList(value: String): List<HighlightCountWrapper> {
        val type = Types.newParameterizedType(List::class.java, HighlightCountWrapper::class.java)
        return moshi.adapter<List<HighlightCountWrapper>>(type).fromJson(value) ?: emptyList()
    }

    @TypeConverter
    fun fromHighlightWrapperList(list: List<HighlightCountWrapper>): String {
        val type = Types.newParameterizedType(List::class.java, HighlightCountWrapper::class.java)
        var adapter: JsonAdapter<List<HighlightCountWrapper>> = moshi.adapter<List<HighlightCountWrapper>>(type)
        return adapter.toJson(list)
    }

 @TypeConverter
    fun toExperienceList(value: String): List<Experience> {
        val type = Types.newParameterizedType(List::class.java, Experience::class.java)
        return moshi.adapter<List<Experience>>(type).fromJson(value) ?: emptyList()
    }

    @TypeConverter
    fun fromExperienceList(list: List<Experience>): String {
        val type = Types.newParameterizedType(List::class.java, Experience::class.java)
        var adapter: JsonAdapter<List<Experience>> = moshi.adapter<List<Experience>>(type)
        return adapter.toJson(list)
    }

@TypeConverter
    fun toImageList(value: String): List<Image> {
        val type = Types.newParameterizedType(List::class.java, Image::class.java)
        return moshi.adapter<List<Image>>(type).fromJson(value) ?: emptyList()
    }

    @TypeConverter
    fun fromImageList(list: List<Image>): String {
        val type = Types.newParameterizedType(List::class.java, Image::class.java)
        var adapter: JsonAdapter<List<Image>> = moshi.adapter<List<Image>>(type)
        return adapter.toJson(list)
    }

那么我的行怎么可能对 SQLite 来说太大了？尤其是有时会毫无问题地返回完全相同的数据？

Answer 1

我发现如何使用 length() 和 substr() 只请求 1MB（CursorWindow 的最大值为 2MB），也许它会help。 （在您的情况下，您可以简单地将请求分成 100 行的块，然后关闭游标，然后重复） 看来你是在存储图片，这种情况下最好把图片存储在内部存储中，只在数据库中存储文件路径。

尤其是有时会毫无问题地返回完全相同的数据？

如果您的意思是完全相同的行（例如从 1000 到 2000 的行），但来自不同的设备，则可能是 CursorWindow 的“最大尺寸”不同，在我的情况下，它似乎是2MB。