title: SQL, Android SQLITE Join
body: <p>I have 2 tables which look like:</p>
  
  <pre><code>Table A
  key1 key2 key3
  1    a    a
  2    a    a
  3    a    a
  
  Table B
  key1 key2 key3
  1    xxx  zzz
  2    yyy  www
  </code></pre>
  
  <p>Now i want to have a big table out of A and B 
  where A.key1 matches B.key1 the content of B is pasted 
  otherwise if no key1 matches default values are pasted</p>
  
  <p>for example</p>
  
  <pre><code>Key1 Key2 Key3 Key5 Key6
  1    a    a    xxx  zzz            
  2    a    a    yyy  www               
  3    a    a    0    0       
  </code></pre>
  
  <p>What is the query?</p>