iOS CoreData批量插入?

查看 Efficiently Importing Data 核心数据编程指南的章节。

我现在和你有同样的问题,只是我要插入10000个对象,大约需要30秒,这对我来说仍然很慢。我正在对插入到上下文中的每1000个托管对象执行[ManagedObjectContext Save](换句话说,我的批处理大小为1000)。我尝试了30种不同的批量大小(从1到10000),在我的例子中,1000似乎是最佳值。

我在找答案 a similar question 当我遇到这个的时候。@弗拉基米尔米特罗维奇的回答在当时很有帮助,因为我知道我不应该每次都保存上下文,但我也在寻找一些示例代码。

现在我有了它,我将提供下面的代码,以便其他人可以看到执行批插入时的情况。

// set up a managed object context just for the insert. This is in addition to the managed object context you may have in your App Delegate.
let managedObjectContext = NSManagedObjectContext(concurrencyType: NSManagedObjectContextConcurrencyType.PrivateQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = (UIApplication.sharedApplication().delegate as! AppDelegate).persistentStoreCoordinator // or wherever your coordinator is

managedObjectContext.performBlock { // runs asynchronously

    while(true) { // loop through each batch of inserts. Your implementation may vary.

        autoreleasepool { // auto release objects after the batch save

            let array: Array<MyManagedObject>? = getNextBatchOfObjects() // The MyManagedObject class is your entity class, probably named the same as MyEntity
            if array == nil { break } // there are no more objects to insert so stop looping through the batches

            // insert new entity object
            for item in array! {
                let newEntityObject = NSEntityDescription.insertNewObjectForEntityForName("MyEntity", inManagedObjectContext: managedObjectContext) as! MyManagedObject
                newObject.attribute1 = item.whatever
                newObject.attribute2 = item.whoever
                newObject.attribute3 = item.whenever
            }
        }

        // only save once per batch insert
        do {
            try managedObjectContext.save()
        } catch {
            print(error)
        }

        managedObjectContext.reset()
    }
}

目标-C

@suragch anwser版本

NSManagedObjectContext * MOC = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
MOC.persistentStoreCoordinator = YOURDB.persistentStoreCoordinator;
[MOC performBlock:^{ 
   // DO YOUR OPERATION
 }];