zoukankan      html  css  js  c++  java
  • ALTER TABLE causes auto_increment resulting key 'PRIMARY'

    修改表为主键的自动增长值时,报出以下错误:
    mysql> ALTER TABLE YOON CHANGE COLUMN id id INT(11) NOT NULL AUTO_INCREMENT ADD PRIMARY KEY (id);
    ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ADD PRIMARY KEY (id)' at line 1


    解决:
    将ID值为0的那条记录或其他大于0且不重复的数据;

    查询重复数据:
    mysql> select id,count(*) as count from yoon group by id having count > 1;
    +------+-------+
    | id   | count |
    +------+-------+
    |    1 |     2 |
    +------+-------+
    1 row in set (0.00 sec)


    mysql> select * from yoon where id =1;
    +------+------+
    | id   | name |
    +------+------+
    |    1 | AAAA |
    |    1 | DDDD |
    +------+------+
    2 rows in set (0.00 sec)


    mysql> delete from yoon where name='DDDD';
    Query OK, 1 row affected (0.00 sec)


    添加表为主键的自动增长值时,依旧报出以下错误:
    mysql> ALTER TABLE YOON CHANGE COLUMN id id INT(11) NOT NULL AUTO_INCREMENT ADD PRIMARY KEY (id);
    ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ADD PRIMARY KEY (id)' at line 1

    原因:
    很多人都忽略了NULL值:
    mysql> select * from yoon where id is null;  
    +------+------+
    | id   | name |
    +------+------+
    | NULL | EEEE |
    +------+------+
    1 row in set (0.00 sec)


    mysql> delete from yoon where id is null;
    Query OK, 1 row affected (0.01 sec)


    mysql> alter table yoon change column id id int(11) not null auto_increment,add primary key(id);
    Query OK, 3 rows affected (0.04 sec)
    Records: 3  Duplicates: 0  Warnings: 0

    or

    alter table yoon modify id int(11) not null auto_increment primary key;

  • 相关阅读:
    java项目中文件含义
    关于反射技术
    Subversion Edge部署
    svn Edge访问规则配置
    redhat开启端口
    关于Ant脚本
    Maven
    版本控制工具
    Oracle了解(一)
    java 空格替换%20
  • 原文地址:https://www.cnblogs.com/hankyoon/p/5169661.html
Copyright © 2011-2022 走看看