mysql
我哦用mysql在表中新添加了一列，添加完显示成功后又出现了一句这段话是什么意思啊？
mysql操作如下
mysql> use student;
database changed
mysql> alter table myemp add column hiredate timestamp not null default current_
timestamp;
query ok, 0 rows affected (0.22 sec)
records: 0 duplicates: 0 warnings: 0