 (
   id INT UNSIGNED AUTO_INCREMENT NOT NULL COMMENT '用户id',
   mail VARCHAR(30) COLLATE utf8_bin NOT NULL COMMENT '用户邮箱',
-  name CHAR(14) COLLATE utf8_bin NOT NULL COMMENT '用户名',
+  name CHAR(20) COLLATE utf8_bin NOT NULL COMMENT '用户名',
   password CHAR(32) COLLATE utf8_bin NOT NULL COMMENT '用户密码',
   create_at TIMESTAMP NOT NULL COMMENT '注册时间',
   PRIMARY KEY (id),

(
  id INT UNSIGNED AUTO_INCREMENT NOT NULL COMMENT '文章id',
  author_id INT UNSIGNED NOT NULL COMMENT '作者id',
  author_name VARCHAR(16) COLLATE utf8_bin NOT NULL COMMENT '作者名',
  content_digest CHAR(100) COLLATE utf8_bin NOT NULL COMMENT '文章摘要',
  update_at TIMESTAMP NOT NULL COMMENT '文章更新时间',
  create_at TIMESTAMP NOT NULL COMMENT '文章创建时间',
  PRIMARY KEY (id),

CREATE TABLE IF NOT EXISTS users_auth
(
  id INT UNSIGNED NOT NULL COMMENT '用户id',
  name CHAR(20) COLLATE utf8_bin NOT NULL COMMENT '用户名',
  auth INT UNSIGNED NOT NULL COMMENT '用户权限',
  PRIMARY KEY (id),
  KEY auth(auth)
