小编sda*_*sad的帖子

我的数据模型中有 2 个实体，如下图所示：

产品：

出席：

我很好地保存了出勤关系的产品！现在，我需要使用特定的 Attendance.objectID 获取产品

我正在尝试以下代码：

func fetchProducts() {
    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    
    let managedContext = appDelegate.managedObjectContext
    
    let fetchRequest = NSFetchRequest(entityName: "Product")
    let attendancePredicate = NSPredicate(format: "attendance.objectID == \(currAttendance.objectID)")
    fetchRequest.predicate = attendancePredicate
    
    print("Att = \(currAttendance.name!)")
    viewTypeSKU.hidden = true
    
    do {
        let results = try managedContext.executeFetchRequest(fetchRequest)
        products = results as! [NSManagedObject]
    } catch let error as NSError {
        print("Could not fetch \(error), \(error.userInfo)")
    }

}

我收到错误： 'Unable to parse the format string "attendance.objectID ==