- //假设已经在项目文件中创建了名为Person的对象(实体,Entity)
- //首先,需要在使用Person实例类的代码头文件中加入:
- #import <uikit uikit.h="">
- #import <coredata coredata.h="">
- #import "Person.h"
- 使用core data的简单代码,创建一个Person实体实例,保存它,然后遍历数据,相当于:select * from persons:
- NSLog(@">>start app ");
- Person *person=(Person *)[NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:[self managedObjectContext]];
- person.name=@"张三";
- NSError *error;
- if (![[self managedObjectContext] save:&error;]) {
- NSLog(@"error!");
- }else {
- NSLog(@"save person ok.");
- }
- NSFetchRequest *request=[[NSFetchRequest alloc] init];
- NSEntityDescription *entity=[NSEntityDescription entityForName:@"Person" inManagedObjectContext:[self managedObjectContext]];
- [request setEntity:entity];
- NSArray *results=[[[self managedObjectContext] executeFetchRequest:request error:&error;] copy];
- for (Person *p in results) {
- NSLog(@">> p.id: %i p.name: %@",p.id,p.name);
- }
- //如果需要删除也很简单:
- [managedObjectContext deleteObject:person];</coredata></uikit>
- //该片段来自于http://www.codesnippet.cn/detail/051220137769.html
来源: http://www.codesnippet.cn/detail/051220137769.html