ios - 在核心数据中添加一个新的独立实体是否需要模型版本控制？

Question

我想在我的项目中添加一个新的核心数据实体。我是否需要为此添加一个新的核心数据模型版本，或者它将在现有版本中工作？该实体是独立的，并且与之前定义的其他实体没有任何关系。

Answer 1

的确，它需要添加一个新的模型版本。但是，添加新实体可以由 lightweight migration 处理。 ，所以至少您不必创建映射模型/编写自定义迁移代码。

更新:

摘自关于轻量级迁移的文章:

In addition, Core Data supports: ... Changing the entity hierarchy

• You can add, remove, rename entities
• You can create a new parent or child entity and move properties up and down the entity hierarchy
• You can move entities out of a hierarchy
• You cannot, however, merge entity hierarchies; if two existing entities do not share a common parent in the source, they cannot share a common parent in the destination

如果你不使用版本控制，你会得到这样的错误:

Error Domain=NSCocoaErrorDomain Code=134100 "(null)" UserInfo={metadata={ NSPersistenceFrameworkVersion = 641; NSStoreModelVersionHashes = { TestEntity1 = ; }; NSStoreModelVersionHashesVersion = 3; NSStoreModelVersionIdentifiers = ( "" ); NSStoreType = SQLite; NSStoreUUID = "F16AD345-02FE-4E94-B11E-3BC337B16568"; "_NSAutoVacuumLevel" = 2; }, reason=The model used to open the store is incompatible with the one used to create the store} with userInfo dictionary { metadata = { NSPersistenceFrameworkVersion = 641; NSStoreModelVersionHashes = { TestEntity1 = ; }; NSStoreModelVersionHashesVersion = 3; NSStoreModelVersionIdentifiers = ( "" ); NSStoreType = SQLite; NSStoreUUID = "F16AD345-02FE-4E94-B11E-3BC337B16568"; "_NSAutoVacuumLevel" = 2; }; reason = "The model used to open the store is incompatible with the one used to create the store"; }

这对我来说似乎是使用版本控制的一个很好的理由)