NSError *error; NSManagedObjectContext *context = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Tz_task_from" inManagedObjectContext:context]; NSFetchRequest *request = [[NSFetchRequest alloc]init]; [request setEntity:entityDesc]; [request setReturnsObjectsAsFaults:NO]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"taskfrom=%@",userid]; [request setPredicate:predicate]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"taskend" ascending:NO]; NSArray*sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor,nil]; [request setSortDescriptors:sortDescriptors]; NSArray *objects = [context executeFetchRequest:request error:&error]; | 1、比较运算符>,<,==,>=,<=,!=
2、范围运算符:IN、BETWEEN
3、字符串本身:SELF
4、字符串相关:
(1)、CONTAINS包含某个字符串 @name CONTAINS[cd] %@ (2)、BEGINSWITH以某个字符串开头
@name BEGINSWITH[c] %@ (3)、ENDSWITH以某个字符串结束
@name ENDSWITH[d] %@
注: [c]不区分大小写 [d]不区分发音符号即没有重音符号 [cd]既不区分大小写,也不区分发音符号。
5、通配符:LIKE
例:[NSPredicate predicateWithFormat:[NSString stringWithFormat:@"customername LIKE[cd] '*%@*'",_searchString]];
6、正则表达式:MATCHES
例:NSString *regex = @"^A.+e$"; //以A开头,e结尾
@"name MATCHES %@",regex
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