Swift5 简单核心数据 NSPredicate 获取

Question

我只是想通过我命名为 "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'Unable to parse the format string "id == 8DF3F2C6741B47C8864D1052C36E2C4D"'。我该如何解决这个问题？

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
}

Answer 1

这是一个格式字符串。而不是

NSPredicate(format: "id = \(id)")

写

NSPredicate(format: "id == %@", id)

Swift5 简单核心数据 NSPredicate 获取

Swift5 Simple Core Data NSPredicate Get

core-data

nspredicate

predicate

swift5