swift - Firebase 重复单元格

Question

在将客户从数据库导入到 TableView 期间，是否可以避免重复具有相同名称内容的单元格？在我的示例中，如果客户 Ben Smith 有两个具有值的 child ，我只需要一个单元格包含他的名字。

这是我的数据库结构...

并在表格 View 中产生结果:

let userID = Auth.auth().currentUser!.uid
    let usersDatabaseRef = Database.database().reference().child("usersDatabase").child(userID).child("Customers")
    usersDatabaseRef.observe(.value, with: { snapshot in
        print("there are \(snapshot.childrenCount) users")
        for child in snapshot.children {
            let childSnap = child as! DataSnapshot
            print("user: \(childSnap.key)")
            let userCustomerSnap = childSnap
            for customer in userCustomerSnap.children.allObjects as! [DataSnapshot] {
                let customerSnap = customer
                let dict = customerSnap.value as! [String: Any]
                let name = dict["Name and surname"]
                let phone = dict["Phone"]
                let company = dict["Company name"]
                let customerID = dict["ID"]
                let email = dict["Email"]
                let nip = dict["Nip1"]
                let postal = dict["Postal code"]
                let street = dict["Street"]
                let town = dict["Town"]
                let myCustomer = CustomerModel(name: name as? String, phone: phone as? String, company: company as? String, customerID: customerID as? String, email: email as? String, nip: nip as? String, postal: postal as? String, street: street as? String, town: town as? String)
                self.candies.append(myCustomer)
                self.filteredCandies.append(myCustomer)
            }
            self.tableViewCustomer.reloadData()

Answer 1

每次找到来自该客户的订单(或数据中“Ben Smith”下代表的任何级别)时，您都会将一个项目添加到列表中。因此，您的列表是订单列表，而不是客户列表。

一般来说，在 NoSQL/Firebase 中，建议根据您想要显示的内容对数据库进行建模。因此，如果您想要客户列表，我会将其存储在数据库中。但考虑到您的数据结构，您也可以在代码中修复它:

usersDatabaseRef.observe(.value, with: { snapshot in
    print("there are \(snapshot.childrenCount) users")
    for child in snapshot.children {
        let childSnap = child as! DataSnapshot
        let myCustomer = CustomerModel(name: child.key, phone: "", company: "", customerID: "", email: "", nip: "", postal: "", street: "", town: ")
        self.candies.append(myCustomer)
        self.filteredCandies.append(myCustomer)
    }

    self.tableViewCustomer.reloadData()
})

或者，仅当新客户的姓名与您之前看到的订单不同时才添加新客户:

var previousName: String = ""
usersDatabaseRef.observe(.value, with: { snapshot in
    print("there are \(snapshot.childrenCount) users")
    for child in snapshot.children {
        let childSnap = child as! DataSnapshot
        print("user: \(childSnap.key)")
        let userCustomerSnap = childSnap
        for customer in userCustomerSnap.children.allObjects as! [DataSnapshot] {
            let customerSnap = customer
            let dict = customerSnap.value as! [String: Any]
            let name = dict["Name and surname"]
            if name != previousName {
                let phone = dict["Phone"]
                let company = dict["Company name"]
                let customerID = dict["ID"]
                let email = dict["Email"]
                let nip = dict["Nip1"]
                let postal = dict["Postal code"]
                let street = dict["Street"]
                let town = dict["Town"]
                let myCustomer = CustomerModel(name: name as? String, phone: phone as? String, company: company as? String, customerID: customerID as? String, email: email as? String, nip: nip as? String, postal: postal as? String, street: street as? String, town: town as? String)
                self.candies.append(myCustomer)
                self.filteredCandies.append(myCustomer)
                previousName = name
            }
        }
    }
    self.tableViewCustomer.reloadData()