title: SQL: join two tables (LEFT OUTER JOIN) then update values
body: <p>Im trying to update a value in one column based on a value in another table.</p>
  
  <p>I can do this if the columns are all in the same table like this:</p>
  
  <pre><code>UPDATE wp_posts 
  SET post_date = REPLACE (post_date, 'X', 'Y') 
  WHERE meta_value = 'Z';
  </code></pre>
  
  <p>But I need to join two tables first before I can update:</p>
  
  <pre><code>SELECT * 
  FROM wp_posts 
  LEFT OUTER JOIN wp_postmeta ON post_id = post_id
  </code></pre>
  
  <p>How can I update based on the two tables I have joined?</p>