Place the custom field values in the custom columns

WordPress - Custom field values in Custom Columns

/*
 * Custom fields in custom admin columns
 */

add_action( 'manage_orders_posts_custom_column', 'my_manage_orders_columns', 10, 2 );

function my_manage_orders_columns( $column, $post_id ) {
  global $post;

	switch( $column ) {

		/* If displaying the 'email' column. */
		case 'user_email_address' :

			/* Get the post meta. */
			$email = get_post_meta( $post_id, 'user_email_address', true );

			/* If no email is found, output a default message. */
			if ( empty( $email ) )
				echo __( 'Unknown' );
			else
				echo $email;

			break;

		/* If displaying the 'order_amount' column. */
		case 'order_amount' :

			/* Get the post meta. */
			$order_amount = get_post_meta( $post_id, 'order_amount', true );

			/* If no order_amount is found, output a default message. */
			if ( empty( $order_amount ) )
				echo __( 'Unknown' );
			else
				echo $order_amount;

			break;

		/* If displaying the 'transaction_id' column. */
		case 'transaction_id' :

			/* Get the post meta. */
			$transaction_id = get_post_meta( $post_id, 'transaction_id', true );

			/* If no transaction_id is found, output a default message. */
			if ( empty( $transaction_id ) )
				echo __( 'Unknown' );
			else
				echo $transaction_id;

			break;

		/* If displaying the 'order_status' column. */
		case 'order_status' :

			/* Get the post meta. */
			$order_status = get_post_meta( $post_id, 'order_status', true );

			/* If no order_status is found, output a default message. */
			if ( empty( $order_status ) )
				echo __( 'Unknown' );
			else
				echo $order_status;

			break;

		/* Just break out of the switch statement for everything else. */
		default :
			break;
	}
}