Show DropDownList in GridView for every row and save every row content in table on asingle button click

Question

In my webform ,I just placed one GridView and in this grid ,want to place three column ,in one column i want to place dropdownlist  ,which is fill from all  ids which is corresponding to first column value (portalId)

Like....|  portalId  |Name   |  DropDownList                  |

            1           |  ABC   |  List related with(portalId)=1|