解析-在特定行后查询 [英] Parse - Query after a specific row
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问题描述
如何查询objectId等于我存储的objectId的特定行之后?
这是我的查询代码:
func queryStory(){
let query = PFQuery(className: "myClassStory")
query.whereKey("isPending", equalTo: false)
query.limit = 1000
query.orderByDescending("createdAt")
query.findObjectsInBackgroundWithBlock { (posts: [PFObject]?, error: NSError?) -> Void in
if (error == nil){
// Success fetching objects
for post in posts! {
if let imagefile = post["userFile"] as? PFFile {
self.userFile.append(post["userFile"] as! PFFile)
self.objID.append(post.objectId!)
self.createdAt.append(post.createdAt!)
}
}
print("Done!")
}
else{
print(error)
}
}
}
这是我的Parse数据库类:
我想要的是仅查询objectId:woaVSFn89t
之后创建的项目.我该怎么办?
解决方案
找到对象后尝试对其进行过滤:
query.findObjectsInBackgroundWithBlock { (posts: [PFObject]?, error: NSError?) -> Void in
if (error == nil){
// Success fetching objects
var thePostTime = NSDate()
for post in posts! {
if post.objectId == "The Object Id You Were Trying To Find" {
thePostTime = post.createdAt!
}
}
for post in posts! {
if post.createdAt!.isGreaterThan(thePostTime) == true {
if let imagefile = post["userFile"] as? PFFile {
self.userFile.append(post["userFile"] as! PFFile)
self.objID.append(post.objectId!)
self.createdAt.append(post.createdAt!)
}
}
}
print("Done!")
}
else{
print(error)
}
}
您会注意到我使用以下方法比较了日期:使用Swift进行NSDate比较 >
How can I query after a specific row where the objectId is equal to a objectId I have stored?
This is my query code:
func queryStory(){
let query = PFQuery(className: "myClassStory")
query.whereKey("isPending", equalTo: false)
query.limit = 1000
query.orderByDescending("createdAt")
query.findObjectsInBackgroundWithBlock { (posts: [PFObject]?, error: NSError?) -> Void in
if (error == nil){
// Success fetching objects
for post in posts! {
if let imagefile = post["userFile"] as? PFFile {
self.userFile.append(post["userFile"] as! PFFile)
self.objID.append(post.objectId!)
self.createdAt.append(post.createdAt!)
}
}
print("Done!")
}
else{
print(error)
}
}
}
This is my Parse database class:
What I want, is to only query the items that was createdAt after the objectId: woaVSFn89t
. How can I do this?
解决方案
Try filtering the objects once you have found them:
query.findObjectsInBackgroundWithBlock { (posts: [PFObject]?, error: NSError?) -> Void in
if (error == nil){
// Success fetching objects
var thePostTime = NSDate()
for post in posts! {
if post.objectId == "The Object Id You Were Trying To Find" {
thePostTime = post.createdAt!
}
}
for post in posts! {
if post.createdAt!.isGreaterThan(thePostTime) == true {
if let imagefile = post["userFile"] as? PFFile {
self.userFile.append(post["userFile"] as! PFFile)
self.objID.append(post.objectId!)
self.createdAt.append(post.createdAt!)
}
}
}
print("Done!")
}
else{
print(error)
}
}
You will notice that I compared the dates using this: NSDate Comparison using Swift
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