Multiple datasouce in Combobox?

Question

i'm using DevExpress now. Now i want to add Combobox with each item is one datasource. Example: I have 2 items in combobox.

If i choose item 1 with querystring is "SElect * from my table1" and bind in Gridview

If i choose item 2 with querystring is "SElect * from my table2" and bind in Gridview

Anyone could help me please, i really need in my project. Thanks in advance!