title: SQL update fields of one table from fields of another one
body: <p>I have two tables:</p>
  
  <pre><code>A [ID, column1, column2, column3]
  B [ID, column1, column2, column3, column4]
  </code></pre>
  
  <p><code>A</code> will always be subset of <code>B</code> (meaning all columns of <code>A</code> are also in <code>B</code>).</p>
  
  <p>I want to update a record with a specific <code>ID</code> in <code>B</code> with their data from <code>A</code> for all columns of <code>A</code>. This <code>ID</code> exists both in <code>A</code> and <code>B</code>.</p>
  
  <p>Is there an <code>UPDATE</code> syntax or any other way to do that without specifying the column names, just saying <em>"set all columns of A"</em>?</p>
  
  <p>I'm using PostgreSQL, so a specific non-standard command is also accepted (however, not preferred).</p>