iOS应用程序coreData与PersistentStore作为静态sqlite数据迁移？ [英] iOS application coreData with PersistentStore as static sqlite Data Migration?

问题描述

应用程序使用来自bundle目录的静态sqlite（初始数据）作为Coredata的持久存储。 sqlite有7个表，其中一个表通过添加额外的列/字段来修改。我如何让coreData了解持久存储（存储）已更改，并需要采取新的更新？
像我们为coredata做的那样，是否有任何模型版本的概念？

解决方案

1>打开您的.xcdatamodeld文件

2>点击编辑器

3>选择添加模型版本...

4>添加您的模型的新版本（添加的新组数据模型）

5>选择主文件，打开文件检查器（右侧面板） p>

6>并在版本核心数据模型下为当前数据模型选择新版本的数据模型

7>

8>转到您的AppDelegate，找到persistStoreCoordinator的创建位置

9>查找此行if（！[_ persistentStoreCoordinator addPersistentStoreWithType：NSSQLiteStoreType configuration：nil URL：storeURL options：nil error：& error]）

10>使用@ {NSMigratePersistentStoresAutomaticallyOption：@YES，NSInferMappingModelAutomaticallyOption：@YES}替换nil选项（实际上在该方法的注释代码中提供）

乐趣！
P.S.这只适用于轻量级迁移。要使迁移成为轻量级迁移，您的更改必须局限于此窄带：

添加或删除属性（属性或关系）。

Make a nonoptional property optional。

重命名属性。

p>

The app is using a static sqlite(initial data) from bundle directory as a persistent store for Coredata. The sqlite has 7 tables of which one table is modified by adding an extra column/field. How does I make coreData understand that the persistent store(store) is changed and it needs to take the new update ? Is there any Model version concept for sqlite like we do for coredata ?

解决方案

For those who doesn't want to dig into documentation and is searching for a quick fix:

1>Open your .xcdatamodeld file

2> click on Editor

3> select Add model version...

4> Add a new version of your model (the new group of datamodels added)

5> select the main file, open file inspector (right-hand panel)

6> and under Versioned core data model select your new version of data model for current data model

7> THAT'S NOT ALL ) You should perform so called "light migration".

8> Go to your AppDelegate and find where the persistentStoreCoordinator is being created

9> Find this line if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error])

10> Replace nil options with @{NSMigratePersistentStoresAutomaticallyOption:@YES, NSInferMappingModelAutomaticallyOption:@YES} (actually provided in the commented code in that method)

Here you go, have fun! P.S. This only applies for lightweight migration. For your migration to qualify as a lightweight migration, your changes must be confined to this narrow band:

Add or remove a property (attribute or relationship).

Make a nonoptional property optional.

Make an optional attribute nonoptional, as long as you provide a default value.

Add or remove an entity.

Rename a property.

Rename an entity.

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