使用Swift Realm,我想从父母的角度来看一个孩子的主人。
简单来说,实体关系可以描述为:
Parent -< Child <- Player
使用给定的Parent,我想获得一个玩家(所有者)列表。
当我尝试查询时,我相信我的查询是错误的;
// Cut-down summary of Realm objects and relationships
public class Parent: Object {
var children = List<Child>()
}
public class Child: Object {
private let parents = LinkingObjects(fromType: Parent.self, property: "children")
private let owners = LinkingObjects(fromType: Player.self, property: "children")
var parent:Parent? {
return self.parents.first
}
var owner: Player? {
return self.owners.first
}
}
public class Player : Object {
public let children = List<Child>()
}
let realm = try! Realm()
self.createPlayers(amount: 5)
let playerList = realm.objects(EYPlayer.self)
XCTAssert(playerList.count == 5)
// In my tests:
let firstParent = realm.objects(Parent.self).first
let firstChild = firstParent?.children.first
let firstPlayer = realm.objects(Player.self).first
// Assign the first player with the first child
try! realm.write {
firstPlayer?.children.append(firstChild!)
}
// give me a list of owners for a given parent
let owners = realm.objects(Parent.self).filter("ANY children.owners.@count > 0")
print (owners)
// Test fails; it says there are 0 results
XCTAssert(owners.count == 1, "Expected: 1, Found: \(owners.count)")
此测试失败:
XCTAssert(owners.count == 1, "Expected: 1, Found: \(owners.count)")
我希望有1位老板。
但相反,我得到0个拥有者。
我做错了什么?
如何使用NSPredicates和Realm获取给定孩子的所有者列表?
非常感谢
编辑:发现我没有添加任何玩家;添加玩家的摘要版本如上所示
答案 0 :(得分:1)
我现在已经解决了这个问题。
执行此操作后,对我的测试进行了一些调整后,查询似乎正在工作,并在我的记录器输出中进行了验证。
let firstParent = realm.objects(Parent.self).first
let firstPlayer = realm.objects(Player.self).first
let firstChild = firstParent?.children.first
XCTAssert(firstChild?.parent == firstParent)
try! realm.write {
firstPlayer!.children.append(firstChild!)
}
let listOfChildren = realm.objects(Parent.self).filter("ANY children.owners.@count > 0")
XCTAssert(listOfChildren.count == 1)
XCTAssert(firstPlayer?.children.count == 1)
for child in listOfChildren {
for (index, eng) in child.children.enumerated() {
if (index == 0) {
XCTAssert(eng.owner != nil)
}
XCTAssert(child.parent == loco)
}
}
测试通过,通过一些控制台日志,我能够验证我的期望。
问题已解决。
关闭。