如何解决对于 ToOne 和 ToMany
最近从 1.0.0 更新到 1.1.1,我的关系代码停止工作,我不确定我到底错过了什么,但直到项目查询似乎正常工作为止。
这就是我所拥有的,我真的可以使用一些帮助来弄清楚我错过了什么
店铺创建:
void initializeUserInventory() async {
await getApplicationDocumentsDirectory().then((dir) {
try {
_quickSaveStore =
Store(getobjectBoxModel(),directory: dir.path + '/quickSaveItems');
_quickactionStore = Store(getobjectBoxModel(),directory: dir.path + '/quickSaveActions');
_categorizedSaveStore = Store(getobjectBoxModel(),directory: dir.path + '/categorizedSaveItems');
_itemCategoryStore = Store(getobjectBoxModel(),directory: dir.path + '/categorizedSaveCategories');
_itemTagsstore = Store(getobjectBoxModel(),directory: dir.path + '/categorizedSaveTags');
} catch (e) {
print(e.toString());
}
}).whenComplete(() {
// Must initialize everything else after completion of store initialization!
_userQuickSaveBox = Box<InitialItem>(_quickSaveStore!);
_quickactionSaveBox = Box<QuickSaveAction>(_quickactionStore!);
_categorizedSaveBox = Box<InitialItem>(_categorizedSaveStore!);
_itemCategoryBox = Box<ItemCategory>(_itemCategoryStore!);
_itemTagsBox = Box<ItemTag>(_itemTagsstore!);
});
}
这里是实体文件: 初始项:
part 'initial_item.g.dart';
@JsonSerializable(explicitToJson: true)
@Entity()
class InitialItem {
String? itemName;
String? inc;
DateTime cacheTime;
DateTime? saveTime;
@Id(assignable: true)
int id;
//#region Category
//
// Functions that are utilized for Saving the item by Category
//
/// Holds the count of how many items the vehicle/WO needs
int? quantity;
/// Any comments the user has added to the item
String? userComment;
/// Category that the item belongs too
final itemCategory = ToOne<ItemCategory>();
/// Allows adding a tag to the saved item
final tags = ToMany<ItemTag>();
//#endregion
InitialItem(
{this.id = 0,this.itemName,this.inc,this.quantity = 1,DateTime? cacheTime,DateTime? saveTime,this.userComment = '',})
: cacheTime = cacheTime ?? DateTime.Now(),saveTime = cacheTime ?? DateTime.Now();
}
项目类别:
part 'item_category.g.dart';
@JsonSerializable(explicitToJson: true)
@Entity()
class ItemCategory {
int id;
String? categoryUid;
String? userUid;
String? categoryName;
String? categoryComment;
@Backlink()
final items = ToMany<InitialItem>();
ItemCategory(
{this.id = 0,this.userUid,this.categoryName,this.categoryUid,this.categoryComment});
}
项目标签:
part 'item_tag.g.dart';
@JsonSerializable(explicitToJson: true)
@Entity()
class ItemTag {
int id;
String? name;
/// Only used for FilterChip display,not saved in any database
@Transient()
bool isSelected;
String? uid;
ItemTag({this.id = 0,this.name,this.isSelected = false,this.uid});
}
标签和类别已经由用户创建并保存在他们的框中。一个项目被传递到视图中,用户可以为项目添加标签,并且可以选择一个类别来保存项目。
/// Attaches the tags that the user selected to the item for saving
void attachTagsToItem() {
// Clear all prevIoUs tags before adding the selected tags
savingItem?.tags.clear();
savingItem?.tags.addAll(enabledTagList);
}
然后,该项目将选定的类别写入到它的 toOne 目标并保存-- saveItem 正确地在此处包含所有内容
bool saveCategorizedItem() {
if (selectedCategory != null) {
// Set the item category
savingItem!.itemCategory.target = selectedCategory;
_userInventoryService.addCategorizedItemToLocal(savingItem!);
return true;
} else {
return false;
}
}
它的保存位置——此时,一切都已检查完毕。我可以调试并查看它们变量中的标签和信息,我可以在 itemCategory 中查看 Category 及其信息。
void addCategorizedItemToLocal(InitialItem saveItem) {
_categorizedSaveBox.put(saveItem);
print('Item saved to categorized database');
}
稍后,我查询保存的每个项目,以便将它们分组到列表中。而此时它只返回InitialItem,并没有拉取关系数据。 toOne 和 toMany 的目标都是空的。
/// Returns all the of Items that have been categorized and saved
List<InitialItem> getAllCategorizedItems() => _categorizedSaveBox.getAll();
------------------------------------------------------------------------------------------
Calling the query in the View Provider's class
void getCategorizedItems() {
_categorizedSaveList = _userInventoryService.getAllCategorizedItems();
notify(ViewState.Idle);
}
然后我尝试使用返回的查询构建列表。 element.itemCategory.target 返回 null,标签也是如此。正如我所说,这一切以前都在 1.0.0 版中工作,升级后失败,没有进行其他更改。一般查询有问题吗?我可以在调试窗口中查看关系,所以我假设设置正确,它似乎没有用原始查询拉出对象。 谁能解释一下我做错了什么?
Widget categorizedList(BuildContext context) {
final saveProvider =
Provider.of<UserInventoryProvider>(context,listen: true);
return GroupedListView<dynamic,String>(
physics: const BouncingScrollPhysics(),elements: saveProvider.categorizedSaveList,groupBy: (element) => element.itemCategory.target!.categoryName,groupComparator: (d1,d2) => d2.compareto(d1),groupSeparatorBuilder: (String value) => Padding(
padding: const EdgeInsets.all(8.0),child: Text(value,textAlign: TextAlign.center,style: TextStyles.kTextStyleWhiteLarge),),indexedItemBuilder: (c,element,index) {
return Container();
},);
}
解决方法
经过评论中的所有讨论,我终于注意到您初始化了多个商店。实际上,您正在使用多个独立数据库,因此关系无法按预期工作。您的 initializeUserInventory()
应该类似于:
void initializeUserInventory() async {
_store = await openStore(); // new shorthand in v1.1,uses getApplicationDocumentsDirectory()
_userQuickSaveBox = _store.box();
_quickActionSaveBox = _store.box();
_categorizedSaveBox = _store.box();
_itemCategoryBox = _store.box();
_itemTagsBox = _store.box();
}
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