title: SQL query about Nested query and NATURAL JOIN
body: <p>I have three tables.
  First table is Activities and second is Members and last is Message.
  Activities has a foreign key named Members_ID and primary key is Activity_ID.
  Members' primary key is Members_ID.
  Message recorded Activity_ID and Members_ID.
  I wanna search about Activities NATURAL JOIN Members and I need a new column count for
  Message's message_ID  where the Activity_ID is the same.</p>
  
  <p>NATURAL JOIN:</p>
  
  <pre><code>SELECT*
      FROM Activities 
          NATURAL JOIN Members 
      WHERE Activities.Members_ID = Members.Members_ID;
  </code></pre>
  
  <p>COUNT(message_ID):</p>
  
  <pre><code>SELECT COUNT(message_ID) 
      FROM Message 
      WHERE Activity_ID = 123;
  </code></pre>
  
  <p>Question is:
  How to search the above two things together?
  I'd like have a table have Activities NATURAL JOIN Members with same Activities.Members_ID
  and a virtual column which is COUNT(message_ID) from table Message.</p>