内部查询解析

Question

我试图链接用户创建的与收件人相关联的票，但我没有得到任何回报，我能够从票表中获取票，但内部查询的匹配似乎没有链接。关闭解析文档，我尝试使用内部查询作为链接或桥梁，如下所示：

let innerQuery = PFQuery(className:"Tickets")
        let query = PFQuery(className: "Messages")

        //get all tickets for current user
        innerQuery.whereKey("user", equalTo: PFUser.current()?.objectId as Any)
        //objectId is ticketId in tickets table
        innerQuery.includeKey("objectId")
        //match to ticketId in messages table
        query.whereKey("ticketId", matchesQuery: innerQuery)

        do {
            let returnedObjects = try query.findObjects()
            for object in returnedObjects {
                let sender = object["sender"] as? String
                }
            }
        } catch {

        }

Answer 1

首先，当我们需要在 Parse Server 中进行内部查询时，我们会将列保存为指针对象。所以这里需要将Message表中的ticketId列保存为Tickets类的Pointer Class。你可以这样保存：

let pointerObj = [“__type": "Pointer", "className": "Tickets", "objectId": "yourClassObjectId"]
messagePraseObj.setValue(pointerObj, forKey: “ticketId")

之后，您可以使用以下代码来完成您的任务。我在我的项目中使用它。 我用过 iOS SDK 1.17.3 和 swift 4。

    let innerQuery = PFQuery.init(className: "Tickets")
    innerQuery.whereKey("user", equalTo: PFUser.current()?.objectId as Any)

    let query = PFQuery.init(className: "Messages")
    query.whereKey("ticketId", matchesQuery: innerQuery)
    query.includeKey("ticketId")

    query.findObjectsInBackground { (returnedObjects, error) in
        if error == nil && returnedObjects != nil {
            for object in returnedObjects! {
                let ticket = object.value(forKey: "ticketId") as! PFObject
                let sender = ticket.value(forKey: "user") as? String ?? ""
                print("User ID: \(sender)")
            }
        }
    }

欲了解更多信息：https://docs.parseplatform.org/ios/guide/#relational-queries

希望对你有所帮助。