mysql新建表示例:
create table employee(
employee_id int unsigned not null auto_increment primary key,
userName varchar(15) not null,
userSex enum('M','F') default 'M',
birth Date);
修改列示例:
alter table employee modify userName varchar(20);
修改列说明:
alter table employee changer userName user_name varchar(20);
删除列:
alter table employee drop userSex;
新增列:
alter table employee add (email varchar(50) null);