CREATE TABLE "user" ( "id" int PRIMARY KEY, "user_name" varchar(255), "password" varchar(255) ); CREATE TABLE "role" ( "id" int PRIMARY KEY, "role_name" varchar(255) ); CREATE TABLE "permission" ( "id" int PRIMARY KEY, "permission_name" varchar(255) ); CREATE TABLE "user_role" ( "user_id" int CONSTRAINT user_id REFERENCES user(id), "role_id" int CONSTRAINT role_id REFERENCES role(id) ); CREATE TABLE "role_permission" ( "role_id" int CONSTRAINT role_id REFERENCES role(id), "permission_id" int CONSTRAINT permission_id REFERENCES permission(id) );