Question

我正在尝试向现有用户表添加一列，但它不起作用。我明白了：

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 'unsigned default 0 after users_id' at line 1

这是我的命令：

root@localhost:test> alter table users add column users_is_active tinyint(3) not null unsigned default 0 after users_id;

除非我没有正确拼写“not null”，我做错了什么？感谢

Answer 1

alter table users添加列users_is_active tinyint（3）not null unsigned default 0 after users_id;

TINYINT(3) UNSIGNED是类型。 NOT NULL不属于TINYINT(3)和UNSIGNED。而是说TINYINT(3) UNSIGNED NOT NULL（等等）。

Answer 2

将unsigned移近tinyint：

alter table users 
  add column users_is_active tinyint(3) unsigned not null default 0
  after users_id;

MySQL alter table命令不起作用

2 个答案: