Mysql报错：ERROR 1697 (HY000): VALUES value for partition 'p0' must have type INT

1.报错原因

执行如下SQL语句时，出现

mysql> create table student
    -> ( id int ,
    ->  name  varchar(20),
    ->  address varchar(20),
    ->  score int,
    ->  birthday datetime
    ->  )
    ->  partition by range (birthday)(
    ->  partition p0 values less than ('1980-01-01') ENGINE = InnoDB,
    ->  partition p1 values less than ('1990-01-01') ENGINE = InnoDB,
    ->  partition p2 values less than ('2000-01-01') ENGINE = InnoDB
    ->  );
ERROR 1697 (HY000): VALUES value for partition 'p0' must have type INT

2.报错原因

将partition by range (birthday)修改成partition by range COLUMNS(birthday)即可。但是为什么这里添加column就可以解决问题呢？

create table student
( id int ,
 name  varchar(20),
 address varchar(20),
 score int, 
 birthday datetime
 )
 partition by range COLUMNS(birthday)(
 partition p0 values less than ('1980-01-01') ENGINE = InnoDB,
 partition p1 values less than ('1990-01-01') ENGINE = InnoDB,
 partition p2 values less than ('2000-01-01') ENGINE = InnoDB
 );