CREATE TABLE Problem_Category_Codes (problem_category_code VARCHAR2, problem_category_description VARCHAR2)
CREATE TABLE Problem_Log (problem_log_id NUMBER, assigned_to_staff_id NUMBER, problem_id NUMBER, problem_category_code VARCHAR2, problem_status_code VARCHAR2, log_entry_date DATETIME, log_entry_description VARCHAR2, log_entry_fix VARCHAR2, other_log_details VARCHAR2)
CREATE TABLE Staff (staff_id NUMBER, staff_first_name VARCHAR2, staff_last_name VARCHAR2, other_staff_details VARCHAR2)
CREATE TABLE Product (product_id NUMBER, product_name VARCHAR2, product_details VARCHAR2)
CREATE TABLE Problem_Status_Codes (problem_status_code VARCHAR2, problem_status_description VARCHAR2)
CREATE TABLE Problems (problem_id NUMBER, product_id NUMBER, closure_authorised_by_staff_id NUMBER, reported_by_staff_id NUMBER, date_problem_reported DATETIME, date_problem_closed DATETIME, problem_description VARCHAR2, other_problem_details VARCHAR2)

Bar chart x axis log entry description y axis the number of log entry description, list by the Y in descending.
SELECT log_entry_description, COUNT(log_entry_description) FROM Problem_Log GROUP BY log_entry_description ORDER BY COUNT(log_entry_description) DESC
SELECT "log_entry_description", COUNT("log_entry_description") FROM "Problem_Log" GROUP BY "log_entry_description" ORDER BY COUNT("log_entry_description") DESC