CoreData 关系循环?
CoreData relationships loops?
我有 2 个实体 Buildings
和 GroupOfBuildings
:
Building1
有:GroupOfBuildings1
Building2
有:GroupOfBuildings1
GroupOfBuildings1
有:Building1
、Building2
和 Building3
关系:
Building <<----> GroupOfBuildings
Building <<--->> GroupOfBuildings
Building <---->> GroupOfBuildings
问题:
GroupOfBuildings
有一组 Buildings
可以在 Buildings
中使用,还包含对 Buildings
的 mainBuildings
引用。最重要的是,Buildings
需要引用 GroupOfBuildings
。这是建立关系的正确方法还是有另一种方法?似乎设置多个(循环)关系不是我应该做的事情。有什么建议吗?
示例代码:
let buildingDescription = NSEntityDescription.entity(forEntityName: "Buildings", in: context)!
let building1 = Buildings(entity: buildingDescription, insertInto: context)
let building2 = Buildings(entity: buildingDescription, insertInto: context)
let building3 = Buildings(entity: buildingDescription, insertInto: context)
let groupOfBuildingDescription = NSEntityDescription.entity(forEntityName: "GroupOfBuildings", in: context)!
let groupOfBuildings1 = GroupOfBuildings(entity: groupOfBuildingDescription, insertInto: context)
groupOfBuildings1.mainBuilding = building1
groupOfBuildings1.groupOfBuildings = Set([building2, building3])
building1.groupOfBuildings = groupOfBuildings1
building2.groupOfBuildings = groupOfBuildings1
注:
我有另一个问题使用相同的数据,但问题不同。
由于命名错误,这很难理解。称呼事物本来的样子,不要将对象名称复数化。 Buildings
应该叫 Building
,GroupOfBuildings
可能是 BuildingGroup
,不知道 'items' 指的是什么...
也就是说在同一个对象之间建立多个关系是没有问题的。你可以有 buildingGroup.mainBuilding
、buildingGroup.otherBuildings
、buildingGroup.extraBuildings
都可以,只要正确命名它们就可以了。
我有 2 个实体 Buildings
和 GroupOfBuildings
:
Building1
有:GroupOfBuildings1
Building2
有:GroupOfBuildings1
GroupOfBuildings1
有:Building1
、Building2
和 Building3
关系:
Building <<----> GroupOfBuildings
Building <<--->> GroupOfBuildings
Building <---->> GroupOfBuildings
问题:
GroupOfBuildings
有一组 Buildings
可以在 Buildings
中使用,还包含对 Buildings
的 mainBuildings
引用。最重要的是,Buildings
需要引用 GroupOfBuildings
。这是建立关系的正确方法还是有另一种方法?似乎设置多个(循环)关系不是我应该做的事情。有什么建议吗?
示例代码:
let buildingDescription = NSEntityDescription.entity(forEntityName: "Buildings", in: context)!
let building1 = Buildings(entity: buildingDescription, insertInto: context)
let building2 = Buildings(entity: buildingDescription, insertInto: context)
let building3 = Buildings(entity: buildingDescription, insertInto: context)
let groupOfBuildingDescription = NSEntityDescription.entity(forEntityName: "GroupOfBuildings", in: context)!
let groupOfBuildings1 = GroupOfBuildings(entity: groupOfBuildingDescription, insertInto: context)
groupOfBuildings1.mainBuilding = building1
groupOfBuildings1.groupOfBuildings = Set([building2, building3])
building1.groupOfBuildings = groupOfBuildings1
building2.groupOfBuildings = groupOfBuildings1
注:
我有另一个问题使用相同的数据,但问题不同。
由于命名错误,这很难理解。称呼事物本来的样子,不要将对象名称复数化。 Buildings
应该叫 Building
,GroupOfBuildings
可能是 BuildingGroup
,不知道 'items' 指的是什么...
也就是说在同一个对象之间建立多个关系是没有问题的。你可以有 buildingGroup.mainBuilding
、buildingGroup.otherBuildings
、buildingGroup.extraBuildings
都可以,只要正确命名它们就可以了。