CONNECTING TABLES WITH FOREIGN KEY SQL ORACLE : HERE IS MY QUESTION
List the number of employees who work in each department.
QUERY

[enter image description here][1]


IT WORKS FINE TILL HERE .BUT WHEN I TRY TO COMBINE WITH ANOTHER TABLE USING THE FOREIGN KEY IT THROWS AN ERROR.ANYONE COULD HELP ME
TO FIND THE ERROR IN MY CODE?
[enter image description here][2]


  [1]: https://i.stack.imgur.com/RwmYc.png
  [2]: https://i.stack.imgur.com/LK0aj.png