mysql中datetime和timestamp的区别 先copy一份文档给大家看： datetime a date and time combination. the supported range is '1000-01-01 00:00:00' to '9999-12-31 23:59:59'. mysql displays datetime values in 'yyyy-mm-dd hh:mm:ss' format, but allow
mysql中datetime和timestamp的区别
先copy一份文档给大家看：
datetime
a date and time combination. the supported range is '1000-01-01 00:00:00' to '9999-12-31 23:59:59'.
 mysql displays datetime values in 'yyyy-mm-dd hh:mm:ss' format, but allows you to assign values to datetime columns using either strings or numbers.
timestamp
a timestamp. the range is '1970-01-01 00:00:00' to partway through the year 2037. 
a timestamp column is useful for recording the date and time of an insert or update operation. 
the first timestamp column in a table is automatically set to the date and time of the most recent operation if you don't assign it a value yourself. 
you can also set any timestamp column to the current date and time by assigning it a null value.
现在开始具体比较：
datetime，字节数为8，取值范围为“1000-01-01 00:00:00——9999-12-31 23:59:59”
               对应java类型为java.sql.timestamp
           insert或update操作时系统不会自动修改其值，不可以设定默认值，为必须字段时必须手动插入，建议使用：new()
               mysql按照yyyy-mm-dd hh:mm:ss对数据进行格式化，允许以字符串和数字的方式提交
eg：insert into time_table(createdate) values(‘2014-06-09 15:01:01’)
或insert into time_table(createdate) values(‘20140609150101’)
timestamp，字节数为4，取值范围为“19700101080001——20380119111407”
对应java类型为java.sql.timestamp
insert或update操作时（且未手动赋值）系统会自动更新、插入当前系统时间，默认值为current_timestamp()
提交手动赋值为null时也会被赋值为当前系统时间，错误时会填入0
使用timestamp一定要注意他的时间范围（见上）。