title: MySQL join two tables and add column values
body: <p>My knowledge of MySQL is not very in depth. If I have two tables that for example look like this:</p>
  
  <pre><code>Table1
  Date        v1  v2  v3
  05/01/2010  26  abc 45
  05/02/2010  31  def 25
  05/03/2010  50  ghi 46
  
  Table2
  Date        v1 v2  v3
  05/01/2010  42 jkl 15
  05/02/2010  28 mno 14
  05/03/2010  12 pqr 64
  </code></pre>
  
  <p>How can I join them in a query by their date and have the sum of table1.v1 and table2.v1 and also have the sum of table1.v3 and table2.v3? V2 should be ignored.</p>