mysql怎么取出最新增加的数据 mysql 如何取出全部数据的25%
mysql \u5982\u4f55\u5728\u663e\u793a\u6240\u6709\u6570\u636e\u7684\u57fa\u7840\u4e0a\u6dfb\u52a0\u67e5\u8be2\u6761\u4ef6\u518d\u5c06\u67e5\u8be2\u7ed3\u679c\u8fd4\u56de\u81f3\u539f\u9875\u9762\u5c11\u4e2a\u5355\u5f15\u53f7\u5427
25%\u5c31\u662f1/4\u6240\u4ee5\u4f60\u8981\u8ba1\u7b97\u51fa\u6570\u636e\u603b\u6570\uff0c\u7136\u540e\u7528\u5206\u9875\u67e5\u8be2\u7684\u65b9\u6cd5\u53d6\u51fa\u4f60\u9700\u8981\u76841/4
取最后注册的一个用户：select * from user order by id desc limit 1
去多个就把上门语句中的1改为其它数值
TO_DAYS(createtime)-TO_DAYS(now())=0表示提取今天注册的用户，TODAYS表示这个日期从0年开始的天数，例如：
select TO_DAYS('1997-10-07');
-> 729669
TO_DAYS(createtime)-TO_DAYS(now()
是将字符串转换为时间，这里做的运算就是表示创建时间等于当前时间，其实这个并不太靠谱。还不如找出最大ID的（如果ID是自动生成的话）
select * from user where createtime = (select max(createtime) from user)
TO_DAYS(createtime)-TO_DAYS(now())=0表示提取今天注册的用户
请查看核桃博客的详细说明，
友情问答2-mysql怎么取出最新增加的数据，
http://www.hetaoblog.com/?p=45
正确的方式是用last_insert_id(),用order by id desc limit 1
或者max(createtime)的方式是不对的
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