title: SQL count after joining two tables
body: <p>I am newbie to SQL, I would like to come up with a count, assume this example with 2 tables:</p>
  
  <pre><code>School(schoolID, name,....)
  Student(StudentID, SchoolID, ...)
  </code></pre>
  
  <p>I tried:</p>
  
  <pre><code>SELECT COUNT(studentID) 
  FROM School s, Student t
  WHERE s.schooldID = t.schoolID
  </code></pre>
  
  <p>How can I get a count of all students across all schools?</p>