MySQL命令行删除表中的一个字段_MySQL
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2022-05-06 10:45:59
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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)
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