update_meta

Source code

function update_meta( $meta_id, $meta_key, $meta_value ) {

	global $wpdb;



	$meta_key = stripslashes($meta_key);



	if ( is_protected_meta( $meta_key ) )

		return false;



	if ( '' === trim( $meta_value ) )

		return false;



	$post_id = $wpdb->get_var( $wpdb->prepare("SELECT post_id FROM $wpdb->postmeta WHERE meta_id = %d", $meta_id) );



	$meta_value = maybe_serialize( stripslashes_deep( $meta_value ) );

	$meta_id = (int) $meta_id;



	$data  = compact( 'meta_key', 'meta_value' );

	$where = compact( 'meta_id' );



	do_action( 'update_postmeta', $meta_id, $post_id, $meta_key, $meta_value );

	$rval = $wpdb->update( $wpdb->postmeta, $data, $where );

	wp_cache_delete($post_id, 'post_meta');

	do_action( 'updated_postmeta', $meta_id, $post_id, $meta_key, $meta_value );



	return $rval;

}