如何在CloudKit中通过creationDate进行查询？ [英] How to query by creationDate in CloudKit?

问题描述

我想从CloudKit获取公共/私人条目的最后X分钟。

I want to fetch the last X minutes of public/private entries from CloudKit.

我尝试了这个效果但失败了：

I tried something in this effect but failed:

    let date = NSDate(timeInterval: -60.0 * 120, sinceDate: NSDate())
    let predicate = NSPredicate(format: "creationDate > %@", date)

但这会得到我的数据，但我不确定我是不是查询所有内容或仅查询某种上限：

But this will get me data, but I'm not sure if I'm querying everything or just to some kind of cap:

    let predicate = NSPredicate(value: true)

我希望能够在一定的时间内查询。如果没有在客户端进行创建排序逻辑，这是否可行？

I want to be able to query by certain amount of time. Is this possible without doing the creation sorting logic on the client side?

这是完整的代码块：

func fetchPublicData(completion: ((records:[AnyObject]) -> Void)!)
{
    let date = NSDate(timeInterval: -60.0 * 120, sinceDate: NSDate())
    let predicate = NSPredicate(format: "creationDate > %@", date)
    let query = CKQuery(recordType: "MyDataRecordType", predicate: predicate)

    let container = CKContainer.defaultContainer()
    let publicDb = container.publicCloudDatabase

    publicDb.performQuery(query, inZoneWithID: nil,
    {
        (results, error) in

        if error != nil
        {
            self.handleError(error)
        }
        else
        {
            // do stuff
        }
    })
}

谢谢。

推荐答案

找到我的o问题。
您需要登录CloudKit仪表板并选中此复选标记框。

Found out my own question. You'll need to log in to CloudKit dashboard and have this checkmark box checked.

一旦选中，您就可以按日期查询：

Once it's checked, you'll be able to query by date like so:

let date = NSDate(timeInterval: -60.0 * 120, sinceDate: NSDate())
let predicate = NSPredicate(format: "creationDate > %@", date)

这里有更详细的文件说明你可以使用哪种NSPredicate用于CloudKit：
https://developer.apple.com/documentation/cloudkit/ckquery#//apple_ref/doc/uid/TP40014043-CH1-SW8

Here's more detailed document of what kind of NSPredicate you can use for CloudKit: https://developer.apple.com/documentation/cloudkit/ckquery#//apple_ref/doc/uid/TP40014043-CH1-SW8

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