Question

我想使用swift更新实体的多个属性，但找不到任何管理它的教程。我已设法使用以下代码更新实体的单个属性：

   //Insert Function
func Insert(dbname : String , attributeName : String , value : String ) {
    let check_empty = entityIsEmpty(dbname)
    if(check_empty != true){

    let saveData = NSEntityDescription.insertNewObjectForEntityForName(dbname, inManagedObjectContext: managedContext)

    // add our data
    saveData.setValue(value, forKey: attributeName)

    //2
    do {
        try managedContext.save()
        //3
        check_DB.append(saveData)

    } catch let error as NSError  {
        print("Could not save \(error), \(error.userInfo)")
    }

    //check_empty
}else{
        //Update procedure
        let fetchRequest = NSFetchRequest(entityName: dbname)

        do {
            let fetchedEntities = try self.managedContext.executeFetchRequest(fetchRequest) as! [SettingInfo]
            fetchedEntities.first?.attributeName = value

            // ... Update additional properties with new values
        } catch {
            // Do something in response to error condition
        }

        do {
            try self.managedContext.save()

        } catch {
            // Do something in response to error condition
        }

}

}

但是如何更新实体的多个属性？例如：实体名称是：dbname 属性名称为：attribute _ name 我想要更新的属性的值是：value

更新：错误消息：

我的数据库结构：

Answer 1

您可以使用对NSManagedEntities的键控访问，因此您可以说

if let entity = fetchedEntities.first {
    entity[attribute_name]=value
}

Answer 2

我用以下代码解决了我的问题：

//Update procedure
                let fetchRequest = NSFetchRequest(entityName: dbname)

                do {
                    let fetchedEntities = try self.managedContext.executeFetchRequest(fetchRequest) as! [SettingInfo]
                    let attribute = fetchedEntities[0] as NSManagedObject
                    attribute.setValue(value , forKey: attributeName)

                    // ... Update additional properties with new values
                } catch {
                    // Do something in response to error condition
                }

                do {
                    try self.managedContext.save()

                } catch {
                    // Do something in response to error condition
                }

如何在swift 2中更新多个核心数据属性

2 个答案: