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iosCoreData框架的使用,对上下文数据的增删改查,

iosCoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接


 

- (void)viewDidLoad {

[super viewDidLoad];



[self _creatTable];//插入数据



// [self _query];// 查询数据





// KVC很霸道,即使readonly通过kvc也可赋值,kvo精华

// Book * book = [[Book alloc]init];

//// book.name = @"book1";

// [book setValue:@"book2" forKey:@"name"];

// NSLog(@"%@",book.name);

}



#pragma mark - _query查询

- (void)_query{

// 初始化模型

NSManagedObjectModel * model = [NSManagedObjectModel mergedModelFromBundles:nil];



// 创建基础库协调器

NSPersistentStoreCoordinator * psc = [[NSPersistentStoreCoordinator alloc]initWithManagedObjectModel:model];



// 获取沙盒路径

NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];

path = [path stringByAppendingPathComponent:@"coreData.sqlite"];

NSLog(@"%@",path);

NSURL * url = [[NSURL alloc]initFileURLWithPath:path];



//为协调器加载基础库路径和基础库类型

[psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:url options:nil error:nil];

// 创建上下文

NSManagedObjectContext * context = [[NSManagedObjectContext alloc]init];

context.persistentStoreCoordinator = psc;





// 初始化查询请求

NSFetchRequest * request = [[NSFetchRequest alloc]initWithEntityName:@"Teacher"];



// 谓词过滤(查询条件)

#pragma mark '='

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name = %@",@"zhangks"];

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name = 'zhangks'"];

#pragma mark '>'

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"age >10"];

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name in %@",@[@"zhangsk",@"jack"]];

#pragma mark 'like'模糊查询

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name like %@",@"zha*"];

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name like %@",@"*zha*"];

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name like %@",@"*zha"];







#pragma mark 'and'和'&&'模糊查询

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name = %@ and age = 19",@"zhangks"];

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name = %@ && age = 19",@"zhangks"];



#pragma mark 'between'模糊查询

// 方式1

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"age between {20,30}"];



// 方式2

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"age between %@",@[@"10",@"29"]];

// predict = [NSPredicate predicateWithFormat:predict.predicateFormat];



// request.predicate = predict;



// 数据排序 ascending=YES顺序,ascending=NO倒序

NSSortDescriptor * sort = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES];

request.sortDescriptors = @[sort];



NSError * error ;

// 执行查询语句

NSArray * array = [context executeFetchRequest:request error:&error];// 查询结果返回的是数组

// NSInteger count = [context countForFetchRequest:request error:&error];

// 查询结果的个数,返回nsinteger





// NSLog(@"%li",count);



/*

// // KVC方式获取

// for (NSManagedObject * student in array) {

// NSLog(@"————————————————————%@,%li",[student valueForKey:@"name"],[[student/Users/zhangxin/Desktop/OC/UI/5.19/5.21coreData/testtestcoredata/testtestcoredata/ViewController.m valueForKey:@"age"] integerValue]);

// }



// // 子类KVC方式获取

// for (Student * student in array) {

// NSLog(@"%li,%@",[student.age integerValue],[student valueForKey:@"name"]);

// }

*///KVC



// 通过映射对象获取

for (Teacher * teacher in array) {

NSLog(@"%@",teacher.name);

}





}



#pragma mark _creatTable

- (void)_creatTable{

// 初始化模型

NSManagedObjectModel * model = [NSManagedObjectModel mergedModelFromBundles:nil];



// 创建基础库协调器

NSPersistentStoreCoordinator * psc = [[NSPersistentStoreCoordinator alloc]initWithManagedObjectModel:model];



// 获取沙盒路径

NSString * path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];

path = [path stringByAppendingPathComponent:@"coreData.sqlite"];

NSLog(@"%@",path);

NSURL * url = [[NSURL alloc]initFileURLWithPath:path];



//为协调器加载基础库路径和基础库类型

[psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:url options:nil error:nil];

// 创建上下文

NSManagedObjectContext * context = [[NSManagedObjectContext alloc]init];

context.persistentStoreCoordinator = psc;





// // 插入数据

// NSManagedObject * student = [NSEntityDescription insertNewObjectForEntityForName:@"Student" inManagedObjectContext:context];

// [student setValue:@"zhangks" forKey:@"name"];

// [student setValue:@(19) forKey:@"age"];

//

// NSManagedObject * teacher = [NSEntityDescription insertNewObjectForEntityForName:@"Teacher" inManagedObjectContext:context];

// [teacher setValue:@"zhqo" forKey:@"name"];



// 插入数据 新建 NSManagedObject subclass类 ,自动根据model中entity(实体)的表创建出类(继承自NSManagedObject,拥有NSManagedObject的属性和方法)所以直接用类名创建即可

// Student * student = [NSEntityDescription insertNewObjectForEntityForName:@"Student" inManagedObjectContext:context];

// student.name = @"jack";

// student.age = @(29);

//

//

//

// Teacher * teacher = [NSEntityDescription insertNewObjectForEntityForName:@"Teacher" inManagedObjectContext:context];

// teacher.name = @"limei";



// 初始化查询请求

NSFetchRequest * request = [[NSFetchRequest alloc]initWithEntityName:@"Teacher"];



// 谓词过滤(查询条件)

// NSPredicate * predict = [NSPredicate predicateWithFormat:@"name = 'limei'"];



// request.predicate = predict;



NSArray * array = [context executeFetchRequest:request error:nil];

for (Teacher * teacher in array) {

Student * student1 = [NSEntityDescription insertNewObjectForEntityForName:@"Student" inManagedObjectContext:context];

student1.name = @"jim";

student1.age = @(12);

student1.relationship = teacher;













NSLog(@"%@,%@",teacher.name,student1.relationship.name);

//// teacher.name = @"liuwu";

//// [context deleteObject:teacher];

//

}



// NSSet * deleteSet = [context deletedObjects];// 删除(未save),执行删除语句后未保存前,缓存中(库表未修改)存储的删除数据

// NSSet * insertSet = [context insertedObjects];//同上



// 保存

NSError * error;

[context save:&error];

}

ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接ios CoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接

 

www.htsjk.Com true http://www.htsjk.com/DB2/20367.html NewsArticle iosCoreData框架的使用,对上下文数据的增删改查,表与表之间的关联,1对多,1对1,谓词查询,多表连接 - (void)viewDidLoad {[super viewDidLoad];[self _creatTable];//插入数据// [self _query];// 查询数据...
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