text: DROP TABLE IF EXISTS `user`;
  DROP TABLE IF EXISTS `role`;
  DROP TABLE IF EXISTS `user_role`;
  DROP TABLE IF EXISTS `role_permission`;
  DROP TABLE IF EXISTS `permission`;
  
  CREATE TABLE `user` (
                          `id` bigint(11) NOT NULL AUTO_INCREMENT,
                          `username` varchar(255) NOT NULL,
                          `password` varchar(255) NOT NULL,
                          PRIMARY KEY (`id`)
  );
  CREATE TABLE `role` (
                          `id` bigint(11) NOT NULL AUTO_INCREMENT,
                          `name` varchar(255) NOT NULL,
                          PRIMARY KEY (`id`)
  );
  CREATE TABLE `user_role` (
                               `user_id` bigint(11) NOT NULL,
                               `role_id` bigint(11) NOT NULL
  );
  CREATE TABLE `role_permission` (
                                     `role_id` bigint(11) NOT NULL,
                                     `permission_id` bigint(11) NOT NULL
  );
  CREATE TABLE `permission` (
                                `id` bigint(11) NOT NULL AUTO_INCREMENT,
                                `url` varchar(255) NOT NULL,
                                `name` varchar(255) NOT NULL,
                                `description` varchar(255) NULL,
                                `pid` bigint(11) NOT NULL,
                                PRIMARY KEY (`id`)
  );
  
  INSERT INTO user (id, username, password) VALUES (1,'user','e10adc3949ba59abbe56e057f20f883e');
  INSERT INTO user (id, username , password) VALUES (2,'admin','e10adc3949ba59abbe56e057f20f883e');
  INSERT INTO role (id, name) VALUES (1,'USER');
  INSERT INTO role (id, name) VALUES (2,'ADMIN');
  INSERT INTO permission (id, url, name, pid) VALUES (1,'/user/common','common',0);
  INSERT INTO permission (id, url, name, pid) VALUES (2,'/user/admin','admin',0);
  INSERT INTO user_role (user_id, role_id) VALUES (1, 1);
  INSERT INTO user_role (user_id, role_id) VALUES (2, 1);
  INSERT INTO user_role (user_id, role_id) VALUES (2, 2);
  INSERT INTO role_permission (role_id, permission_id) VALUES (1, 1);
  INSERT INTO role_permission (role_id, permission_id) VALUES (2, 1);
  INSERT INTO role_permission (role_id, permission_id) VALUES (2, 2);
  