CREATE TABLE Document_Sections (section_id NUMBER, document_code VARCHAR2, section_sequence NUMBER, section_code VARCHAR2, section_title VARCHAR2)
CREATE TABLE Document_Structures (document_structure_code VARCHAR2, parent_document_structure_code VARCHAR2, document_structure_description VARCHAR2)
CREATE TABLE Roles (role_code VARCHAR2, role_description VARCHAR2)
CREATE TABLE Users (user_id NUMBER, role_code VARCHAR2, user_name VARCHAR2, user_login VARCHAR2, password VARCHAR2)
CREATE TABLE Functional_Areas (functional_area_code VARCHAR2, parent_functional_area_code VARCHAR2, functional_area_description VARCHAR2)
CREATE TABLE Images (image_id NUMBER, image_alt_text VARCHAR2, image_name VARCHAR2, image_url VARCHAR2)
CREATE TABLE Document_Functional_Areas (document_code VARCHAR2, functional_area_code VARCHAR2)
CREATE TABLE Documents (document_code VARCHAR2, document_structure_code VARCHAR2, document_type_code VARCHAR2, access_count NUMBER, document_name VARCHAR2)
CREATE TABLE Document_Sections_Images (section_id NUMBER, image_id NUMBER)

what are the different role codes for users, and how many users have each?, and I want to sort in descending by the role_code.
SELECT role_code, COUNT(*) FROM Users GROUP BY role_code ORDER BY role_code DESC
SELECT "role_code", COUNT(*) FROM "Users" GROUP BY "role_code" ORDER BY "role_code" DESC