NSString stringWithFormat不需要的结果

Question

我想像这样制作sql select语句：

NSLog(@"sql = %@",[NSString stringWithFormat:@"select * from Table1 Where ID = %i AND  '%@' = strftime('%Y',startDate)",ID,date]);

但它打印给我：

sql = select * from Table1 Where ID = 1 AND  '2012' = strftime('Y',startDate)

％Y变为Y，我怎么能阻止这个？

Answer 1

添加另一个%以转义%字符：

NSLog(@"sql = %@",[NSString stringWithFormat:@"select * from Table1 Where ID = %i AND  '%@' = strftime('%%Y',startDate)",ID,date]);

Answer 2

添加类似NSLog(@"sql = %@",[NSString stringWithFormat:@"select * from Table1 Where ID = %i AND '%@' = strftime('%%Y',startDate)",ID,date]);

的％