CoreData的学习记录(2)

来源：互联网发布：安卓虚拟机for mac 编辑：程序博客网时间：2024/06/05 06:15
1.判断是不是重复创建的方法
- (BOOL)createTeamWithName:(NSString *)teamName city:(NSString *)teamCity{    //不加判断的方法//    if (!teamName || !teamCity) {//        return NO;//    }//    //    Team *teamObject = [NSEntityDescription insertNewObjectForEntityForName:@"Team" inManagedObjectContext:self.managedObjectContext];//    teamObject.name = teamName;//    teamObject.city = teamCity;//    //    return YES;        if (!teamName || !teamCity) {        return NO;    }        Team *teamObject = [self getTeamInfoByName:teamName];    if (nil == teamObject) {        teamObject = [NSEntityDescription insertNewObjectForEntityForName:@"Team" inManagedObjectContext:self.managedObjectContext];    }        teamObject.name = teamName;    teamObject.city = teamCity;        return YES;}- (Team *)getTeamInfoByName:(NSString *)teamName{    Team *teamObject = nil;        NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];        NSEntityDescription *teamEntity = [NSEntityDescription entityForName:@"Team" inManagedObjectContext:self.managedObjectContext];    [fetchRequest setEntity:teamEntity];        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name == %@", teamName];    [fetchRequest setPredicate:predicate];    [fetchRequest setFetchLimit:1];        NSError *error = NULL;    NSArray *array = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];    if (error) {        NSLog(@"Error : %@\n", [error localizedDescription]);    }        if (array && [array count] > 0) {        teamObject = [array objectAtIndex:0];    }        fetchRequest = nil;        return teamObject;}
0 0