title: sql query list number of employees a manager manages
body: <p>I'm doing a small assignment for a database class of mine.
  I need to write an sql query to list the last names of all employee managers followed by the number of employees they manage.
  This is what the command for inserting an employee into a table looks like:</p>
  
  <pre><code>INSERT INTO Employee (Emp_No, Emp_Fname, Emp_Lname, Emp_Status,
  Emp_Salary, Emp_Comm, Emp_HireDate, Emp_Mgr_Emp_No, Job_Title, Dept_No)
  VALUES (7566, 'Mary', 'Jones', 'active', 2975, NULL, '02-APR-92', 7839,'Manager', 20);
  </code></pre>
  
  <p>This is what I currently have for a query:</p>
  
  <pre><code>SELECT emp_lname, COUNT(emp_no) "No_of_Employees"
  FROM Employee
  WHERE job_title = ('Manager', 'President')
      AND emp_mgr_emp_no IS NOT NULL
  GROUP BY emp_lname
  </code></pre>
  
  <p>Which gives something like this:</p>
  
  <pre><code>EMP_LNAME             No_of_Employees
  Blake                 1
  Clark                 1
  Jones                 1
  </code></pre>
  
  <p>How would I modify it to list the number of employees for each manager (Including the President, who manages the 3 managers).</p>