title: Mysql query, populate a value based on other
body: <pre><code>meta_id | post_id  |         meta_key   |      meta_value
  ----------------------------------------------------------
  19368   |    5716  | _wpbdp[fields][8]  |
  19369   |    5716  | _wpbdp[fields][9]  |    124_ico.jpg    
  19370   |    5716  | _wpbdp[fields][10] |
  </code></pre>
  
  <p>This is my mysql table. I want that if for a postid the metakey <code>_wpbdp[fields][9]</code> has some value assigned(124_ico.jpg) in this case, then _wpbdp[fields][10] metavalue is updated to 124_img.jpg</p>
  
  <p>Any help with the query would be great.</p>