怎么删除唯一约束?菜鸟求救!! 表名 nnn 列名 myname(可以为空) 想删除唯一约束 ALTER TABLE nnn drop UNIQUE (myname);删不掉 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 show create table nnn;贴一下内容。 mysql> show create table nnn;+-------+----------------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+-------+----------------------------------------------------------------------------------------------------------------------------------------+| nnn | CREATE TABLE `nnn` ( `id` int(11) NOT NULL auto_increment, `myname` varchar(20) default NULL, PRIMARY KEY (`id`), UNIQUE KEY `myname` (`myname`)) ENGINE=InnoDB DEFAULT CHARSET=gb2312 |+-------+----------------------------------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec)大哥让你久等了!!! mysql> show create table `nnn`;+-------+------------------------------------| Table | Create Table+-------+------------------------------------| nnn | CREATE TABLE `nnn` ( `id` int(11) NOT NULL AUTO_INCREMENT, `myname` varchar(20) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `myname` (`myname`)) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+------------------------------------1 row in set (0.00 sec)mysql> DROP INDEX `myname` ON `nnn`;Query OK, 0 rows affected (0.13 sec)Records: 0 Duplicates: 0 Warnings: 0mysql> show create table `nnn`;+-------+-------------------------------| Table | Create Table+-------+-------------------------------| nnn | CREATE TABLE `nnn` ( `id` int(11) NOT NULL AUTO_INCREMENT, `myname` varchar(20) DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+-------------------------------1 row in set (0.00 sec)mysql> 或者 alter table `nnn` drop `myname`;mysql> show create table `nnn`;+-------+------------------------------------| Table | Create Table+-------+------------------------------------| nnn | CREATE TABLE `nnn` ( `id` int(11) NOT NULL AUTO_INCREMENT, `myname` varchar(20) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `myname` (`myname`)) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+------------------------------------1 row in set (0.00 sec)mysql> alter table `nnn` drop `myname`;Query OK, 0 rows affected (0.14 sec)Records: 0 Duplicates: 0 Warnings: 0mysql> show create table `nnn`;+-------+-------------------------------| Table | Create Table+-------+-------------------------------| nnn | CREATE TABLE `nnn` ( `id` int(11) NOT NULL AUTO_INCREMENT, `myname` varchar(20) DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+-------------------------------1 row in set (0.00 sec)mysql> 两个有关联的表的循环问题 php函数调用,公司邮箱发送邮件的问题 读网站问题 十万火急!!考试系统 评分问题?叩谢了 大家提供些信息吧,想租个空间 求助!从ASP转PHP 不会配置. 用SAJAX做的留言本在IE下不兼容,急~~~~` 帮忙给个递归算法 ie7ie8和360下怎么去掉input的默认x 新人关于strftime()函数求助 MYSQL与Smarty的应用 求教PHP算法问题
+-------+------------------------------------------
---------------------------------------------------
-------------------------------------------+
| Table | Create Table |
+-------+------------------------------------------
---------------------------------------------------
-------------------------------------------+
| nnn | CREATE TABLE `nnn` (
`id` int(11) NOT NULL auto_increment,
`myname` varchar(20) default NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `myname` (`myname`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312 |
+-------+------------------------------------------
---------------------------------------------------
-------------------------------------------+
1 row in set (0.00 sec)大哥让你久等了!!!
+-------+------------------------------------
| Table | Create Table
+-------+------------------------------------
| nnn | CREATE TABLE `nnn` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`myname` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `myname` (`myname`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+------------------------------------
1 row in set (0.00 sec)mysql> DROP INDEX `myname` ON `nnn`;
Query OK, 0 rows affected (0.13 sec)
Records: 0 Duplicates: 0 Warnings: 0mysql> show create table `nnn`;
+-------+-------------------------------
| Table | Create Table
+-------+-------------------------------
| nnn | CREATE TABLE `nnn` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`myname` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+-------------------------------
1 row in set (0.00 sec)mysql>
+-------+------------------------------------
| Table | Create Table
+-------+------------------------------------
| nnn | CREATE TABLE `nnn` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`myname` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `myname` (`myname`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+------------------------------------
1 row in set (0.00 sec)mysql> alter table `nnn` drop `myname`;
Query OK, 0 rows affected (0.14 sec)
Records: 0 Duplicates: 0 Warnings: 0mysql> show create table `nnn`;
+-------+-------------------------------
| Table | Create Table
+-------+-------------------------------
| nnn | CREATE TABLE `nnn` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`myname` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+-------------------------------
1 row in set (0.00 sec)mysql>