我正在尝试使用@Query作为数据源在SwiftUI视图中创建一个选择器视图。
不知道我缺少什么？我需要在我的模型中有一个id吗？

@Environment(\.modelContext) var modelContext
@Query var customers: [Customer]
@State private var selectedCustomer: Customer?

Section {
    Picker("", selection: $selectedCustomer) {
Text("SelectCustomer").tag(Optional<String>(nil))

        ForEach("", id: \.self){ customer in 
              Text(customer.clientName).tag(customer as Customer?)
        }
    }
}

import Foundation
import SwiftData

@Model
class Customer {
    var dateCreated: Date
    var clientName: String
    var clientEmail: String
    var streetAddress: String
    var city: String
    var state: String
    var zipCode: String
    var contactPerson: String
    var contactEmail: String
    var phone: String
    var notes: String
}
// init ...

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