title: mysql combine two tables
body: <p>I have two tables, table_a and table_b:</p>
  
  <p>table_a:</p>
  
  <pre><code>city 
  --------
  tokoyo 
  london 
  </code></pre>
  
  <p>table_b:</p>
  
  <pre><code>zipcode  
  -------
  23675
  11290
  </code></pre>
  
  <p>How to combine table_b to table_a, like this:</p>
  
  <p>table_a:</p>
  
  <pre><code>city          zipcode
  --------      --------
  tokoyo        23675
  london        11290
  </code></pre>