关于ubunut上的mysql错误

大家来看看这个，我用mysql query brower 添加表的时候出现的错误，设置字符集的时候出现错误，大家来帮我看看什么意思
CREATE TABLE `forum`.`asd` (
  `asdad` VARCHAR  CHARACTER SET gb2312 COLLATE gb2312_chinese_ci NOT NULL
)
ENGINE = MyISAM
CHARACTER SET gb2312 COLLATE gb2312_chinese_ci;
我点击执行的时候出现这样的错误：
Error executing SQL commands to create table.
MySQL Error Nr. 1064
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 'CHARACTER SET gb2312 COLLATE gb2312_chinese_ci NOT NULL
)
ENGINE = MyISAM
CHARAC' at line 2　　　　　　

CREATE TABLE `b2b`.`asd` (
  `asdad` VARCHAR(255)  CHARACTER SET gb2312 COLLATE gb2312_chinese_ci NOT NULL
)
ENGINE = MyISAM
CHARACTER SET gb2312 COLLATE gb2312_chinese_ci;　　　　　　

varchar没有指定长度　　　　　　

玩SQL前还是先认真学习一下吧。