sql server 2008 - How to change row color in datagridview by comparing two columns from different tables using vb.net? -

no success!

if user of tblcon billmonth of tbltrns exists in tbltrns highlight rows of tblcon red color

code:

 private sub checkexist()  each row datagridviewrow in datagridview1.rows          conobj = new sqlconnection(constr)         conobj.open()         dim qry string = "select * tbltrns username=@username , bill_month=@bill_month"         cmdobj = new sqlcommand(qry, conobj)         cmdobj.parameters.addwithvalue("@bill_month", datetimepicker1.text)         cmdobj.parameters.addwithvalue("@username", (row.cells("user").value.tostring))          drobj = cmdobj.executereader()      if drobj.hasrows         row.defaultcellstyle.backcolor = color.red      end if     next     conobj.close() end sub 

query grid

 public function getdata() dataview      conobj = new sqlconnection(constr)     conobj.open()     cmdobj = new sqlcommand     dsobj = new dataset     daobj = new sqldataadapter()      dim selectqry = "select username[user],doj[connection date],packagename[package],profilename[profile],billing[payment],fees[fees],connectionstatus[status] tblcon"      cmdobj.commandtext = selectqry     cmdobj.connection = conobj     daobj.selectcommand = cmdobj     daobj.fill(dsobj)     tvobj = dsobj.tables(0).defaultview      return tvobj     conobj.close()  end function 

query changed in getdata no success. please guide ...........................................................................................................................................................................................................................................

public function getdata() dataview      conobj = new sqlconnection(constr)     conobj.open()     cmdobj = new sqlcommand     dsobj = new dataset     daobj = new sqldataadapter()      dim selectqry = dim selectqry = "select username[user],doj[connection date],packagename[package],profilename[profile],billing[payment],fees[fees],conn‌​‌​‌​ectionstatus[status], (select isnull(count(*), 0) tbltrns tbltrns.username = tblcon.username , bill_month = '" & datetimepicker1.text & "') [comparison] tblcon"      cmdobj.commandtext = selectqry     cmdobj.connection = conobj     daobj.selectcommand = cmdobj     daobj.fill(dsobj)     tvobj = dsobj.tables(0).defaultview      return tvobj     conobj.close()  end function 

i recommend fill new column in grid value comparison , set it's visibility false. can subselect or left join on second table (if wish example post query fills grid).

based on comparison column can use cellpainting event of gridview. this:

private sub grdgridview_cellpainting(byval sender object, byval e system.windows.forms.datagridviewcellpaintingeventargs) handles grdgridview.cellpainting     if e.rowindex >= 0          if grdgridview.rows(e.rowindex).cells("colcomparison").value <> "0" , not isnothing(grdgridview.rows(e.rowindex).cells("colcomparison").value)             e.cellstyle.backcolor = color.orangered             e.cellstyle.selectionbackcolor = color.indianred         end if      end if end sub