When user start editing row in gridview he see next:

Is it possible to put dropdownlistbox with data from db in editbox?
GridView get data from DB. Autogeneratecolumns = true. My GridView take data from different tables.
Ya it is possible you have to set EditItemTemplete field in Grid view. Consider the following like which contain same answer. Grid View EditItemTemplete
In this article there has been shown that how to appear dropdownlist in edit mode of grid view...
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