sql关于日期查询

select * from clothe where check_datatime between '2009-11-19' and '2009-11-20';

select * from clothe where datediff(day,check_datatime, current_date)=1   这句不知为什么有错误呢

select * from clothe where year(check_datatime)=2009
select * from clothe where year(check_datatime)=2009 and month(check_datatime)=11
select current_date;
select date(now());
select now();
select current_date()-1;
select sysdate();
select datediff(2,'2009-09-01','2009-09-18');

参考
http://hi.baidu.com/qlglandzjl/blog/item/3e8cfda6bd50579fd0435873.html
http://hi.baidu.com/flashdata/blog/item/3da943eda17810d1b31cb14b.html