我目前正在研究核心数据,我有以下代码
NSManagedObjectContext *managedObjContxt = [self managedObjectContext];
NSFetchRequest *fetchReq = [[NSFetchRequest alloc] initWithEntityName:@"BDEvent"];
NSMutableArray *fetchedObj= [[managedObjContxt executeFetchRequest:fetchReq error:nil] mutableCopy];
现在我的 fetchedObj 数组包含
<_PFArray 0x7b78d4e0>(
<BDEvent: 0x7b78cf40> (entity: BDEvent; id: 0x7b78be60 <x-coredata://066794C5-FA98-4D76-B306-C62CF65563F2/BDEvent/p1> ; data: {
name = rock;
status = "D1";
timestamp = "18-02-2015 12:10:10";
}),
<BDEvent: 0x7b78d1f0> (entity: BDEvent; id: 0x7b78be70 <x-coredata://066794C5-FA98-4D76-B306-C62CF65563F2/BDEvent/p2> ; data: {
name = Illa;
status = "D1";
timestamp = "18-02-2015 12:15:01";
}),
<BDEvent: 0x7b78d290> (entity: BDEvent; id: 0x7b78be80 <x-coredata://066794C5-FA98-4D76-B306-C62CF65563F2/BDEvent/p3> ; data: {
name = john;
status = "EXIT|D2";
timestamp = "18-02-2015 12:25:05";
})
)
现在我想根据状态创建 2 个数组
Array1 将包含没有 EXIT 状态的时间戳值,Array2 将包含具有 EXIT 状态的时间戳值。
如何实现?
最佳答案
要获取带有“退出”代码的数组,请像这样向您的提取请求添加谓词。
NSManagedObjectContext *managedObjContxt = [self managedObjectContext];
NSFetchRequest *fetchReq = [[NSFetchRequest alloc] initWithEntityName:@"BDEvent"];
//add this line
fetchReq.predicate = [NSPredicate predicateWithFormat:@"status contains 'EXIT'"];
NSMutableArray *fetchedObj= [[managedObjContxt executeFetchRequest:fetchReq error:nil] mutableCopy];
要获取没有“EXIT”代码的数组,请使用以下谓词,
fetchReq.predicate = [NSPredicate predicateWithFormat:@"NOT (status contains 'EXIT')"];
关于ios - 从核心数据数组对象创建新数组?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/28583927/