title: how to find 0 value records by comparing two tables
body: <p>The question is 
  "find project managers those who don't manage any projects , list name and id"</p>
  
  <p><a href="https://i.stack.imgur.com/JIPOw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JIPOw.png" alt="Project manager table and Projects table"></a> </p>
  
  <p>first table is "PM" and second table is "Projects"
  How to write this query ? I tried the following query but it didnt work.</p>
  
  <pre><code>select a.ID,a.name 
  from PM a,Projects b
  where a.ID=b.ID
  group by a.name
  having COUNT(b.ID)=0; 
  </code></pre>