如何防止在分析时重复输入? [英] How to prevent duplicate entry on parse?
问题描述
我试图保存要分析的歌曲信息,但是如果该歌曲已经存在于分析中,我希望我的代码什么也不做.
I' trying to save song info to parse, but if the song already exist in parse I want my code just do nothing.
我在下面尝试过此代码:
I've tried this code below:
var Music = PFObject(className:"Musics")
var query = PFQuery(className:"Musics")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
// The find succeeded.
println("Successfully retrieved \(objects!.count) scores.")
// Do something with the found objects
if let objects = objects as? [PFObject] {
for object in objects {
var songTitle = object.objectForKey("songTitle") as? String
if songTitle != title {
Music["createdBy"] = PFUser.currentUser()
Music["songTitle"] = title
Music["albumCover"] = imageFile
Music["songArtist"] = artist
Music.saveInBackgroundWithBlock {
(success: Bool, error: NSError?) -> Void in
if (success) {
println("succeed")
} else {
// There was a problem, check error.description
println("error jeh")
}
}
}else{
println("song already exist")
}
}
}
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
}
上面的代码在日志中给出以下结果:
the code above give below result on log:
成功检索到4个分数. 歌曲已经存在 成功检索到4个分数. 歌曲已经存在 成功检索到4个分数. 歌曲已经存在 成功检索到4个分数. 歌曲已经存在 成功 成功 成功 成功 成功 成功 成功 成功 成功 成功 成功 成功
Successfully retrieved 4 scores. song already exist Successfully retrieved 4 scores. song already exist Successfully retrieved 4 scores. song already exist Successfully retrieved 4 scores. song already exist succeed succeed succeed succeed succeed succeed succeed succeed succeed succeed succeed succeed
为什么我的for循环比Objects.count循环更多?以及如何防止在分析时出现重复项?
Why my for loop , looping more than the Objects.count? and how can I prevent dupiclate entry on parse?
给我任何建议,与obj c或swift无关
give me any advice, doesn't matter in obj c or swift
推荐答案
我建议在Parse Cloud代码上实现一个简单的beforeSave触发器,以便检查新的输入歌曲是否已经存在(基本上,您将制作一个或多个字段唯一性.例如:
I suggest to implement a simple beforeSave trigger, on Parse Cloud code, in order to check if the new entry song already exist (basically you're going to make one or more field uniques. For example:
Parse.Cloud.beforeSave("Musics", function(request, response) {
var newEntrySong = request.object;
var querySongs = new Parse.Query("Musics");
querySongs.equalTo("title", newEntrySong.get("title"));
querySongs.equalTo("description", newEntrySong.get("description"));
// this could be a sort of signature for your song, to make more unique (skipping spaces and new lines for example)
querySongs.equalTo("md5Title", newEntrySong.get("md5Title"));
querySongs.first({
success: function(temp) {
response.error({errorCode:123,errorMsg:"Song already exist!"});
},
error: function(error) {
response.success();
}
});
});
希望有帮助.
这篇关于如何防止在分析时重复输入?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!