MySQL命令行删除表中的一个字段
先看看删除之前的表结构: mysql select * from test; +------+--------+----------------------------------+------------+------------+------------+------------+ | t_id | t_name | t_password | t_birth | birth | birth1 | birth2 | +----
<p>先看看删除之前的表结构:
mysql> select from test; +------+--------+----------------------------------+------------+------------+------------+------------+ | t_id | t_name | t_password | t_birth | birth | birth1 | birth2 | +------+--------+----------------------------------+------------+------------+------------+------------+ | 1 | name1 | 12345678901234567890123456789012 | NULL | 1990-01-01 | 0000-00-00 | 2013-01-01 | | 2 | name2 | 12345678901234567890123456789012 | 2013-01-01 | NULL | 0000-00-00 | 2013-01-01 | +------+--------+----------------------------------+------------+------------+------------+------------+ 2 rows in set (0.00 sec) 执行删除命令,使用drop关键字。 基本的语法为:alter table <表名> drop column <字段名>; 具体的命令如下: mysql> alter table test drop column birth1; Query OK, 0 rows affected (0.13 sec) Records: 0 Duplicates: 0 Warnings: 0 看看删除后的结果,是不是已经没有birth1字段了? mysql> select from test; +------+--------+----------------------------------+------------+------------+------------+ | t_id | t_name | t_password | t_birth | birth | birth2 | +------+--------+----------------------------------+------------+------------+------------+ | 1 | name1 | 12345678901234567890123456789012 | NULL | 1990-01-01 | 2013-01-01 | | 2 | name2 | 12345678901234567890123456789012 | 2013-01-01 | NULL | 2013-01-01 | +------+--------+----------------------------------+------------+------------+------------+ 2 rows in set (0.00 sec) 关于MySQL中根据生日计算年龄的SQL语句日期函数,本文就介绍这么多,希望对大家有所帮助,谢谢!