vb.net - SQL Server database not getting updated -

i using following code, database not getting updated:

dim update new sqlcommand("update fagr set fagrn=@fagrn,fagru=@fagru fagrc=@fagrc", connection)  update.parameters.add(new sqlparameter("@fagrc", sqldbtype.nchar, 3)) update.parameters.add(new sqlparameter("@fagrn", sqldbtype.nvarchar, 50)) update.parameters.add(new sqlparameter("@fagru", sqldbtype.nchar, 3))  dim integer = 0 while < datagridview1.rows.count     try         update.parameters(0).value = datagridview1.rows(i).cells(0).tostring         update.parameters(1).value = datagridview1.rows(i).cells(1).tostring         update.parameters(2).value = datagridview1.rows(i).cells(2).tostring         vartemp1 = update.executenonquery()         i=i+1      catch ex exception         msgbox("exception:" & vbcrlf & ex.message)             me.close()     end try loop 

'in similar insert query first row of grid inserted in database. other records not inserted no error shown.

first, make sure you're referring right columns:

dim fagrc datagridviewcolumn = datagridview1.columns("fagrc") dim fagrn datagridviewcolumn = datagridview1.columns("fagrn") dim fagru datagridviewcolumn = datagridview1.columns("fagru") 

datagridviewcell.tostring not return cell value. reflector:

public mustinherit class datagridviewcell      public overrides function tostring() string         return string.concat(new string() {"datagridviewcell { columnindex=", me.columnindex.tostring(cultureinfo.currentculture), ", rowindex=", me.rowindex.tostring(cultureinfo.currentculture), " }"})     end function  end class 

do this:

dim id string = nothing  each row datagridviewrow in datagridview1.rows     if (not row.isnewrow)         id = row.cells(fagrc.index).value.tostring()         if (string.isnullorempty(id))             throw new applicationexception("fagrc missing.")         else             update.parameters(0).value = id             update.parameters(1).value = row.cells(fagrn.index).value.tostring()             update.parameters(2).value = row.cells(fagru.index).value.tostring()             if (update.executenonquery() <= 0)                 throw new applicationexception("could not update fagrc value '" & id & "'.")             end if         end if     end if next