- (void)viewDidLoad {
[super viewDidLoad];
//获取模型文件的路径
NSString *path=[[NSBundle mainBundle]pathForResource:@"Cart" ofType:@"momd"];
//利用模型文件创建被管理模型对象
NSManagedObjectModel *managedObjectModel=[[NSManagedObjectModel alloc]initWithContentsOfURL:[NSURL fileURLWithPath:path]];
//创建持久化存储协调器对象
NSPersistentStoreCoordinator *persistentStoreCoordinator=[[NSPersistentStoreCoordinator alloc]initWithManagedObjectModel:managedObjectModel];
//指定持久化存储文件的路径
NSString *dbPath=[NSHomeDirectory() stringByAppendingPathComponent:@"Documents/cart1.sqlite"];
//添加一个持久化存储对象，第1个参数指存储的类型，url：指持久化存储的文件路径
[persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:[NSURL fileURLWithPath:dbPath] options:nil error:nil];
//初始化对象
_managedObjectContext=[[NSManagedObjectContext alloc]init];
_managedObjectContext.persistentStoreCoordinator=persistentStoreCoordinator;
//[self addData];
//[self updateData];
[self deleteDataByID:2];
[self displayAllData];
}
//向数据文件中添加数据
-(void)addData
{
//根据模型图中的模型名获取新的实例对象
Customer *customer=[NSEntityDescription insertNewObjectForEntityForName:@"Customer" inManagedObjectContext:_managedObjectContext];
customer.customerID=[NSNumber numberWithInt:2];
customer.userName=@"zhangsan";
customer.password=@"11111";
ShoppingCartMaster *master=[NSEntityDescription insertNewObjectForEntityForName:@"ShoppingCartMaster" inManagedObjectContext:_managedObjectContext];
master.cartID=[NSNumber numberWithInt:2000];
master.customerID=[NSNumber numberWithInt:2];
ShoppingCartDetail *detail1=[NSEntityDescription insertNewObjectForEntityForName:@"ShoppingCartDetail" inManagedObjectContext:_managedObjectContext];
detail1.cartID=[NSNumber numberWithInt:2000];
detail1.productID=[NSNumber numberWithInt:12];
detail1.productName=@"iphone5";
detail1.price=[NSDecimalNumber decimalNumberWithString:@"4000"];
ShoppingCartDetail *detail2=[NSEntityDescription insertNewObjectForEntityForName:@"ShoppingCartDetail" inManagedObjectContext:_managedObjectContext];
detail2.cartID=[NSNumber numberWithInt:2000];
detail2.productID=[NSNumber numberWithInt:23];
detail2.productName=@"iphone6";
detail2.price=[NSDecimalNumber decimalNumberWithString:@"5000"];
customer.cart=master;
[master addDetailObject:detail1];
[master addDetailObject:detail2];
//如果用户对数据做了修改
if([_managedObjectContext hasChanges]){
//进行持久化存储到文件中
BOOL ret=[_managedObjectContext save:nil];
if(ret){
NSLog(@"add successed!");
}
}
}
//显示数据
-(void)displayAllData
{
//进行数据查询请求的对象，参数指要查询的模型实体名
NSFetchRequest *request=[[NSFetchRequest alloc]initWithEntityName:@"Customer"];
NSString *name=@"Qianfeng";
//设置谓词对象（可以用于对数据记录筛查）
NSPredicate *predicate;
//精确匹配查找
//predicate=[NSPredicate predicateWithFormat:@"userName=%@",name];
//模糊查找,查询以name中的字符串开始，不区分大小写的记录
predicate=[NSPredicate predicateWithFormat:@"userName like [cd] %@",[NSString stringWithFormat:@"%@*",name]];
//设置请求中的谓词对象（筛查条件）
//request.predicate=predicate;
//在被管理对象上下文中执行查询请求，返回该模型对象数组
NSArray *result=[ _managedObjectContext executeFetchRequest:request error:nil];
for(Customer *cus in result){
//获取其cart属性
ShoppingCartMaster *master=cus.cart;
NSLog(@"customerID:%@,userName:%@,password:%@,cartID:%@",cus.customerID,cus.userName,cus.password,master.cartID);
//获取其详情，NSSet类型，转换为NSArray
NSArray *array=[master.detail allObjects];
//显示该customer的cart中所有的product
for(ShoppingCartDetail *detail in array){
NSLog(@"pid:%@,pname:%@,price:%@",detail.productID,detail.productName,detail.price);
}
}
}
-(void)updateData
{
NSFetchRequest *request=[[NSFetchRequest alloc]initWithEntityName:@"Customer"];
NSPredicate *predicate=[NSPredicate predicateWithFormat:@"customerID=2"];
request.predicate=predicate;
//查询出需要修改的对象
NSArray * result=[_managedObjectContext executeFetchRequest:request error:nil];
if(result.count>0){
//取出需要修改的对象，直接对其属性值进行修改
Customer *customer=result[0];
customer.userName=@"lisi";
if([_managedObjectContext hasChanges]){
if([_managedObjectContext save:nil]){
NSLog(@"update ok!");
}
}
}else{
NSLog(@"没有找到需要修改的记录！");
}
}
//根据id删除某条记录
-(void)deleteDataByID:(int)cid
{
//查找要删除的记录对象
NSFetchRequest *request=[[NSFetchRequest alloc]initWithEntityName:@"Customer"];
NSPredicate *predicate=[NSPredicate predicateWithFormat:@"customerID=%d",cid];
request.predicate=predicate;
NSArray *array=[_managedObjectContext executeFetchRequest:request error:nil];
if(array.count>0){
//取出要删除的对象
Customer *customer=array[0];
//在当前被管理对象上下文中删除对象
[_managedObjectContext deleteObject:customer];
if([_managedObjectContext hasChanges]){
if([_managedObjectContext save:nil]){
NSLog(@"delete successed!");
}else{
NSLog(@"delete error!");
}
}
}else{
NSLog(@"没有找到要删除的对象");
}
}