[英]ios swift parse: how to collect pointer data
我有這個查詢:
var query = PFQuery(className: "CardSet")
query.whereKey("user", equalTo: PFUser.currentUser())
query.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if (error == nil) {
// found
}else{
println(error.userInfo)
}
}
結果看起來像這樣:
<CardSet: 0x7c892120, objectId: 2yty7cpnyF, localId: (null)> {
ACL = "<PFACL: 0x7be65450>";
lesson = "<Lesson: 0x7beaabd0, objectId: JV7trFTx5Z>";
name = "I am your CardSet";
public = 1;
user = "<PFUser: 0x7be834a0, objectId: baz8ObNsmM>";
}
類“ CardSet”具有指向類“課程”的指針“課程”。 如何在查詢結果中提供Lesson.name? 還是我需要第二次查詢? 由於要解析的請求量很大,這會很糟糕...? 有什么更好的方法可以在一個查詢中獲取所有指向的數據?
您可以使用includeKey
方法告訴Parse獲取相關對象:
var query = PFQuery(className: "CardSet")
query.whereKey("user", equalTo: PFUser.currentUser())
query.includeKey("lesson")
query.findObjectsInBackgroundWithBlock { (objects: [AnyObject]!, error: NSError!) in
for cardset in objects {
var lesson = cardset["lesson"] as PFObject
var name = lesson["name"] as String
println("retrieved related lesson: \(post) with name: \(name)")
}
}
在文檔的“ 關系查詢”部分中提到。
您傳遞了一個對象數組,因此必須從該數組獲取CardSet:
query.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if (error == nil) {
for object in objects { //note: if objects is always of size 1, just use objects[0]
var cardset = object as CardSet //get the entry
var lesson = cardset.lesson
}
}else{
println(error.userInfo)
}
})
首先,您必須使用includekey,然后在findobjectwithdatablock中將數據另存為PFObject->如果數據為PFUser,另存為PFUser,否則另存為PFObject
范例:
var veriable = (PFUser)()
YourQueryFindObjectBlock {
self.veriable = result["pointerCol"] as PFUser // if pointer has user data
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.