ASP.Net Merge Data Table with Primary Key and show in Grid

If your rows are appending in 2 data table merge then  you must declare a primary key after creating the data table and it will prevent appending the rows of final merge table.


            Dim rodt = getDBTable("select hr as Region, count(ro) as c from kpa_forms where  del= 0 group by hr")
            rodt.PrimaryKey = New System.Data.DataColumn() {rodt.Columns(0)}
            Dim mydt = getDBTable("select hr as Region, count(ro) as c from kpa_forms2 where  del= 0 group by hr")
            mydt.PrimaryKey = New System.Data.DataColumn() {mydt.Columns(0)}
            mydt.Merge(rodt)
            gvOtherAdmin.DataSource = mydt
            gvOtherAdmin.DataBind()