title: SQL Inner join more than two tables
body: <p>I can currently query the join of two tables on the equality of a foreign/primary key in the following way.</p>
  
  <pre><code> $result = mysql_query("SELECT * FROM `table1` 
                           INNER JOIN 
                         `table2` ON table1.primaryKey=table2.table1Id");
  </code></pre>
  
  <p>I'd like to extend this to multiple tables (all with the same foreign keys). I am trying the following code which is not returning anything. Can anyone point out what I'm doing wrong?</p>
  
  <pre><code> $result = mysql_query("SELECT * FROM `table1` 
                          INNER JOIN `table2` 
                          INNER JOIN table3 
                          ON table1.primaryKey=table2.table1Id=table3.table1Id");
  </code></pre>