Hello Adrian

Can you please try adding "UNION ALL" at the end of your query, and let me know if that works?

Hi again Adrian

Unfortunately, if that doesn't work, you can prepare a MySQL view (a stored query), which will return the data that you need, call it e.g. “view1” and then build a wpDataTabled based on a simple query like “SELECT * FROM view1″.

Please note some this when working with the server-side processing feature:

• Please do not use “LIMIT” in the SELECT statement. wpDataTables adds it automatically and it will be overridden.
• Please do not use “ORDER BY” in the SELECT statement. wpDataTables has its own sorting engine so it makes no sense to use MySQL’s sorting, since it will be overridden. Also, server-side processing feature adds this part of statement automatically when users trigger the sorting on the front-end, and having it in initial statement may cause the table to crash.

Please let me know if that helps.