I am working with a Wordpress site and have created a custom page in /home/planmyme/public_html/php/ with the name response.php. On this page I am getting a value to insert in the wp_postmeta table (value examples: transaction ID, purchase ID, order ID, or item name), but I am not able to insert it.

I am using the code below as a test. I do not understand how to achieve this, or if there is any need of a database connection to run the query.

$metakey    = "_menu_item_type";
$metavalue  = "WordPress' database interface is like Sunday Morning: Easy.";

$wpdb->query( $wpdb->prepare( 
        INSERT INTO $wpdb->wp_postmeta
        ( post_id, meta_key, meta_value )
        VALUES ( %d, %s, %s )
) );

Getting this error

Fatal error: Call to a member function query() on a non-object in /home/planmyme/public_html/php/response.php on line 56

If anybody has an idea how to do this, please let me know.

  • 1
    I'm sure this is a duplicate. Try to search for WP_USE_THEMES on this site to find out how to include WordPress in an external script. But why don't you include your script directly into WordPress via plugin or a page template?
    – birgire
    Jun 30, 2014 at 14:07
  • 1
    Have you defined "global $wpdb;" in your function ?
    – Domain
    Sep 2, 2014 at 5:44

2 Answers 2


The error message basically says that $wpdb is not an object so you can't call any methods on it. As we can't see where $wpdb is defined in the source you posted it's hard to tell any further details.

Are you even including wordpress in your external file? You need to require wp-load.php to use the wordpress functions and classes in an external application.


At the moment, your PHP file doesn't recognize $wpdb object.

To utilize WordPress functions within your PHP file, you should first add WordPress support by adding below to the top of your file:

<?php require('/the/path/to/your/wp-blog-header.php'); ?>

Then you can use $wpdb - after defining it:

<?php global $wpdb; ?>

Finally, you should use either the table prefix specifically or let $wpdb do it for you. Later is preferred so a change in table prefix won't affect your PHP file. Hence your SQL should be changed to:

INSERT INTO $wpdb->postmeta

..instead of $wpdb->wp_postmeta

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