Coredata simple teaching (2)

1. coredata is easy to write, easy to manage, difficult to find errors, comprehensive, and highly correlated

2. A brief introduction to the query method

 

 1 #pragma mark -  2 - (NSMutableArray *) findAll { 3     NSManagedObjectContext * cxt = [self managedObjectContext]; 4      5     NSEntityDescription * entityDescription = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:cxt]; 6     NSFetchRequest * request = [[NSFetchRequest alloc] init]; 7     [request setEntity:entityDescription]; 8      9     NSSortDescriptor * sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];10     [request setSortDescriptors:@[sortDescriptor]];11     12     NSError * error = nil;13     NSArray * listData = [cxt executeFetchRequest:request error:&error];14     NSMutableArray * resListArray = [[NSMutableArray alloc] init];15     16     for (Person * handle in listData) {17         Person * person = [[Person alloc] init];18         person.name = handle.name;19         person.age = handle.age;20         21         [resListArray addObject:person];22     }23     24     return resListArray;25 }

 

Coredata simple teaching (2)