Swift5简单核心数据nspredicate get

我只是试图通过一个名为“id”的字符串类型的属性访问核心数据中的记录。下面一直抱怨“无法分析格式字符串”id==8df3f2c6741b47c8864d1052c36e2c4d“。我怎样才能解决这个问题?

private func getEntity(id: String) -> NSManagedObject? {
    var myEntity: NSManagedObject?

    let fetchRequest = NSFetchRequest<NSManagedObject>(entityName: "MyEntity")
    fetchRequest.predicate = NSPredicate(format: "id = \(id)")
    do {
        var tempArray = try getCurrentManagedContext().fetch(fetchRequest)
        myEntity = tempArray.count > 0 ? tempArray[0] : nil
    } catch let error as NSError {
        print("get failed ... \(error) ... \(error.userInfo)")
    }

    return myEntity
}