Question

I am trying to write an Oracle query for a homework assignment. The assignment is to write one query to return the employee_id, job_id, hire_date and department_id of all employees and a second query listing employee_id, job_id, start_date and department_id from the job_hist table and combine the results as one single output. Make sure you suppress duplicates in the output.

Code I Have:

SELECT employee_id AS "Employee ID", job_id AS "Job Id", TO_CHAR(NULL) hire_date "Hire     Date", department_id AS "Department Id",
FROM employees
UNION
SELECT employee_id AS "Employee Id", job_id AS "Job Id", TO_CHAR(NULL) start_date "Start     Date",department_id AS "Department Id", 
FROM job_history;

Error I am getting:

ORA-00923: FROM keyword not found where expected

From what I can tell in the book, the sequence looks right. Any help would be great!

Code after removing the commas:

SELECT employee_id AS "Employee ID", job_id AS "Job Id", TO_CHAR(NULL) hire_date "Hire     Date", department_id AS "Department Id"
FROM employees
UNION
SELECT employee_id AS "Employee Id", job_id AS "Job Id", TO_CHAR(NULL) start_date "Start     Date",department_id AS "Department Id" 
FROM job_history;

Answer 1

SELECT employee_id AS "Employee Id", job_id AS "Job Id", TO_CHAR(hire_date,'yyyy-mm-dd') AS "Some date", department_id AS "Department Id"
FROM employees
UNION
SELECT employee_id AS "Employee Id", job_id AS "Job Id", TO_CHAR(start_date,'yyyy-mm-dd') AS "Some date",department_id AS "Department Id"
FROM job_history;

Is this working?