CREATE TABLE Document_Drafts (document_id INT, draft_number INT, draft_details VARCHAR)
CREATE TABLE Ref_Document_Status (document_status_code CHAR, document_status_description VARCHAR)
CREATE TABLE Addresses (address_id INT, address_details VARCHAR)
CREATE TABLE Ref_Shipping_Agents (shipping_agent_code CHAR, shipping_agent_name VARCHAR, shipping_agent_description VARCHAR)
CREATE TABLE Documents (document_id INT, document_status_code CHAR, document_type_code CHAR, shipping_agent_code CHAR, receipt_date DATETIME, receipt_number VARCHAR, other_details VARCHAR)
CREATE TABLE Employees (employee_id INT, role_code CHAR, employee_name VARCHAR, other_details VARCHAR)
CREATE TABLE Draft_Copies (document_id INT, draft_number INT, copy_number INT)
CREATE TABLE Ref_Document_Types (document_type_code CHAR, document_type_description VARCHAR)
CREATE TABLE Roles (role_code CHAR, role_description VARCHAR)
CREATE TABLE Documents_Mailed (document_id INT, mailed_to_address_id INT, mailing_date DATETIME)
CREATE TABLE Circulation_History (document_id INT, draft_number INT, copy_number INT, employee_id INT)

Show a bar chart about how many employees does each role have?, display x axis from high to low order please.
SELECT role_description, COUNT(*) FROM Roles AS T1 JOIN Employees AS T2 ON T1.role_code = T2.role_code GROUP BY T2.role_code ORDER BY role_description DESC
SELECT "role_description", COUNT(*) FROM "Roles" AS "T1" JOIN "Employees" AS "T2" ON "T1"."role_code" = "T2"."role_code" GROUP BY "T2"."role_code" ORDER BY "role_description" DESC NULLS LAST