Complex query is supported through the following means:

• INNER JOIN
  
• SQL View
  
• PHP array. 
  

With INNER JOIN, editing is supported but limited to the primary table. When using with SQL View, keep in mind that editing is not possible.  

Please see: Complex Query demo

Alternatively, you can use array to popular datagrid (commercial license only). Please see phpGrid omplex Sql Query Support through PHP Array