MagicalRecord 增查改删 基本用法

#pragma mark  删除数据- (void)deleteData{    // delete数据库中所有人         [Person MR_truncateAll];    [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];        // 根据条件delete特定的某个人    NSArray *personsdelete = [Person MR_findByAttribute:@"name" withValue:@"kun" andOrderBy:nil ascending:YES];    NSLog(@"%lu",(unsigned long)[personsdelete count]);            // NSPredicate    NSPredicate *peopleFilter = [NSPredicate predicateWithFormat:@"name CONTAINS %@",@"gao"];    NSArray *people = [Person MR_findAllWithPredicate:peopleFilter];    for (Person *person in people) {                [person MR_deleteEntity];            }        [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];}#pragma mark  查询数据- (void)allData{    NSArray *persons = [Person MR_findAll];        NSLog(@"%lu",(unsigned long)[persons count]);        for (Person *persontemp in persons) {                NSLog(@"name:%@----age:%@",persontemp.name,persontemp.age);    }        //查找所有的Person并按照 name排序。    NSArray *personsSorted = [Person MR_findAllSortedBy:@"name" ascending:YES];        //查找所有age属性为3的Person记录。    NSArray *personsAgeEuqals3 = [Person MR_findByAttribute:@"age" withValue:[NSNumber numberWithInt:3]];        //查找数据库中的第一条记录    Person *person = [Person MR_findFirst];}#pragma mark  改- (void)alert{    NSArray *wellperson = [Person MR_findByAttribute:@"name" withValue:@"gao" andOrderBy:@"age" ascending:YES];    for (Person*persontemp in wellperson) {        persontemp.name = @"kun";    }    [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];}#pragma mark  增加数据- (void)addData{    for (int i = 0; i < 10; i ++) {        Person *myPerson = [Person MR_createEntity];        myPerson.name = [NSString stringWithFormat:@"gao%d",i];        myPerson.age = [NSNumber numberWithInteger:i];        [[NSManagedObjectContext MR_defaultContext] MR_saveToPersistentStoreAndWait];    }}

在AppDelegate加上这一句

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {        [MagicalRecord setupCoreDataStackWithStoreNamed:@"data.sqlite"];    // Override point for customization after application launch.    return YES;}