title: "column ambiguously defined"
body: <p>So I'm totally having a hard time on comprehending SQL this semester. I'm really not confident on the knowledge I have in SQL and I'm trying to work on this exercise where it says:</p>
  
  <p>A SELECT statement to retrieve a list of employees with  the columns <code>DEPARTMENT_ID , DEPARTMENT_NAME , FULL_NAME, JOB_TITLE</code>  where  FULL_NAME is the First name and Last name concatenated with a space between them  for those employees that  their  Job title contains the word 'Sales'. The list must be sorted by   job title and department name.</p>
  
  <p>So far, I came up with this</p>
  
  <pre><code>SELECT department_id, 
      department_name, 
      first_name || ' ' || last_name as Full_name, 
      job_title
  FROM departments d, employees e, jobs j
  WHERE d.department_id=e.department_id 
  HAVING job_title LIKE '%Sales%';
  </code></pre>
  
  <p>and the error says:</p>
  
  <pre><code>Error starting at line 1 in command:
  select department_id, department_name, first_name || ' ' || last_name as Full_name, job_title
  from departments d, employees e, jobs j
  where d.department_id=e.department_id 
  having job_title like '%Sales%'
  Error at Command Line:1 Column:8
  Error report:
  SQL Error: ORA-00918: column ambiguously defined
  00918. 00000 -  "column ambiguously defined"
  *Cause:    
  *Action:
  </code></pre>
  
  <p>Any tips and help will do.</p>