以前都是用FMDB的, 经过封装, FMDB的使用还是很方便的, 多种方法增删改查都可以一行代码实现, 并且不需要拼写sql语句, 最近测试下FMDB的效率, 还是比较慢的, 删改查效率和coredata效率差不多少, 但是添加数据效率慢的不是一点点, 测试插入一个简单的Model类10w次, CoreData用时3~4s, FMDB用时大于66s! 慢了十几倍! 所以, 个人认为, 如果不需要增删改查大量数据, 还是用fmdb比较方便, 但是如果需要同时添加上万条数据, 则使用CoreData来存储数据, 如果数据量比较小, 还是觉得使用更简单一点.

作为一个程序开发者, 应该的态度是接受变化, 拥抱变化, 不是吗?

首先是MagicRecord的配置

直接使用CoreData需要在AppDelegate中配置相关的代码, 所以, 使用MagicRecord时候也需要做相同的配置.

//配置CoreData, MagicRecord提供了以下几种方法. 意义顾名思义, 不解释!+ (void) setupCoreDataStack;+ (void) setupCoreDataStackWithInMemoryStore;+ (void) setupAutoMigratingCoreDataStack;+ (void) setupCoreDataStackWithStoreNamed:(MR_nonnull NSString *)storeName;+ (void) setupCoreDataStackWithAutoMigratingSqliteStoreNamed:(MR_nonnull NSString *)storeName;+ (void) setupCoreDataStackWithStoreAtURL:(MR_nonnull NSURL *)storeURL;+ (void) setupCoreDataStackWithAutoMigratingSqliteStoreAtURL:(MR_nonnull NSURL *)storeURL;例如:- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.        [MagicalRecord setupCoreDataStackWithAutoMigratingSqliteStoreNamed:@"MyDatabase.splite"];        return YES;}其次需要在程序终止代码中写上如下代码:// 程序将要终止时候执行的代码- (void)applicationWillTerminate:(UIApplication *)application {    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.    // Saves changes in the application's managed object context before the application terminates.    [self saveContext];// 程序终止的时候清理CoreData相关配置.    [MagicalRecord cleanUp];}

所有关于数据存储的操作, 不外乎增删改查! 本文例子将按照增删改查的分类来编写.

增添数据:

//添加记录的方法就是, 先创建一个对应的实体, 赋值之后, 将实体保存起来.Person *person = [Person MR_createEntity];person.firstName = @"韦";person.lastName = @"东方";person.age = 20;//添加修改属性之后, 将实体的状态保存下来[[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];

修改数据:

//修改数据的思路是这样的, 首先还是查询, 先查出来要修改的数据, 然后修改相关的属性, 最后保存当前的状态即可! 主要还是查询数据, 按照一定的条件查询出来想要的数据, 然后按照自己的需要操作数据.Person *person = [Person MR_findFirstByAttribute:@"age" withValue:@20];    if (person) {        person.age = 21;        [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];    }

删除数据:

// 删除数据的顺序是, 先查找出要删除的数据, 然后执行下面方法删除实体, 最后将删除后的状态保存下来.- (BOOL) MR_deleteEntity;- (BOOL) MR_deleteEntityInContext:(MR_nonnull NSManagedObjectContext *)context;+ (BOOL) MR_deleteAllMatchingPredicate:(MR_nonnull NSPredicate *)predicate;+ (BOOL) MR_deleteAllMatchingPredicate:(MR_nonnull NSPredicate *)predicate inContext:(MR_nonnull NSManagedObjectContext *)context;//保存删除后的状态[[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];

查询数据:

//查询的话, 方法太多了, 整个分类都是`NSManagedObject (MagicalFinders)`, 共有几十种方法可以用来查询, 满足不同的查询效果, 包含排序, 可以使用谓词(NSPredicate)来封装. 部分方法如下:+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAll;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllInContext:(MR_nonnull NSManagedObjectContext *)context;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllSortedBy:(MR_nonnull NSString *)sortTerm ascending:(BOOL)ascending;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllSortedBy:(MR_nonnull NSString *)sortTerm ascending:(BOOL)ascending inContext:(MR_nonnull NSManagedObjectContext *)context;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllSortedBy:(MR_nonnull NSString *)sortTerm ascending:(BOOL)ascending withPredicate:(MR_nullable NSPredicate *)searchTerm;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllSortedBy:(MR_nonnull NSString *)sortTerm ascending:(BOOL)ascending withPredicate:(MR_nullable NSPredicate *)searchTerm inContext:(MR_nonnull NSManagedObjectContext *)context;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllWithPredicate:(MR_nullable NSPredicate *)searchTerm;+ (MR_nullable MR_NSArrayOfNSManagedObjects) MR_findAllWithPredicate:(MR_nullable NSPredicate *)searchTerm inContext:(MR_nonnull NSManagedObjectContext *)context;+ (MR_nullable instancetype) MR_findFirst;+ (MR_nullable instancetype) MR_findFirstInContext:(MR_nonnull NSManagedObjectContext *)context;+ (MR_nullable instancetype) MR_findFirstWithPredicate:(MR_nullable NSPredicate *)searchTerm;+ (MR_nullable instancetype) MR_findFirstWithPredicate:(MR_nullable NSPredicate *)searchTerm inContext:(MR_nonnull NSManagedObjectContext *)context;+ (MR_nullable instancetype) MR_findFirstWithPredicate:(MR_nullable NSPredicate *)searchterm sortedBy:(MR_nullable NSString *)property ascending:(BOOL)ascending;