title: Insert value in wp_postameta in MySQL
body: <p>In <strong>wp_postmeta</strong> I have a meta_key <strong>limit_usage_to_x_items</strong> I want to make the meta_value for this field '1'</p>
  
  <p>What SQL line can I use to do this?</p>
  
  <p>My knowledge in SQL is quite basic so I'd appreciate any help</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>I've been advised to use the following code</p>
  
  <pre><code>UPDATE `wp_postmeta` SET `meta_value`='1' WHERE `post_id` = '$1' AND `meta_key` = 'limit_usage_to_x_items'
  </code></pre>
  
  <p>When I do this it tells me 0 rows affected. I don't understand why...</p>
  
  <p>Thank you</p>