第一页： MySQL字符集创建及CRUD操作

1、MySQL数据库创建时指定默认的字符集

CREATE database $DN_NAME DEFAULT CHARACTER SET utf8mb4 -- UTF-8 Unicode COLLATE utf8mb4_general_ci

注解：

>  utf8mb4 -- UTF-8 Unicode：字符集；mb4是在utf8的基础上支持了imoji表情。
>  utf8mb4_general_ci：是字符排序方式；
>  mysql 创建database时最好能明确指定字符集，防止字符混乱的情况发生。

2 数据库用户的增删查改

• MySQL用户的创建

CREATE USER 'username'@'host' IDENTIFIED BY 'password';
CREATE USER 'dog'@'localhost' IDENTIFIED BY '123456';
CREATE USER 'pig'@'192.168.1.101_' IDENDIFIED BY '123456';
CREATE USER 'pig'@'%' IDENTIFIED BY '123456';
CREATE USER 'pig'@'%' IDENTIFIED BY '';
CREATE USER 'pig'@'%';

• 单用户授权及其级联授权；

  GRANT privileges ON databasename.tablename TO 'username'@'host'
  GRANT ALL privileges ON $DB_NAME.$TAB_NAME to '$USER_NAME'@'$HOST_IP' identified by '$RANDOM_STRING';
  GRANT privileges ON databasename.tablename TO 'username'@'host' WITH GRANT OPTION;

• 用户MySQL口令修改

  SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');
  SET PASSWORD = PASSWORD("newpassword");
  SET PASSWORD FOR 'pig'@'%' = PASSWORD("123456");

• 用户权限撤销

  REVOKE privilege ON databasename.tablename FROM 'username'@'host';

• 用户权限查看；

  SHOW GRANTS FOR 'pig'@'%';

• 用户删除

  DROP USER 'username'@'host';