Tukukkk

first of all, following is my codes:

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load



    'Establish connection with sql server. Fill the data in data grid view (dgvData)



    For i As Integer = 2 To dgvData.Columns.Count() - 1



        dgvSettings.Rows.Add(dgvData.Columns(i).HeaderText, 0, 100, "High")



    Next



End Sub



Public Sub comparevalues()



    For z As Integer = 2 To dgvData.ColumnCount - 1



        If dgvData.Rows(0).Cells(z).Value.ToString() > dgvSettings.Rows(z - 2).Cells(2).Value.ToString() Then



            MsgBox("Value Exceed Maximum Limit")



            dgvAlert.Rows.Add(False, dgvData.Rows(0).Cells(1).Value.ToString(), dgvData.Columns(z).HeaderText.ToString(), dgvData.Rows(0).Cells(z).Value.ToString(), "Unacknowledged", dgvSettings.Rows(z - 2).Cells(3).Value.ToString())



        ElseIf dgvData.Rows(0).Cells(z).Value.ToString() < dgvSettings.Rows(z - 2).Cells(1).Value.ToString() Then



            MsgBox("Value Below Minimum Limit")



            dgvAlert.Rows.Add(False, dgvData.Rows(0).Cells(1).Value.ToString(), dgvData.Columns(z).HeaderText.ToString(), dgvData.Rows(0).Cells(z).Value.ToString(), "Unacknowledged", dgvSettings.Rows(z - 2).Cells(3).Value.ToString())



        Else

            'in range, do nothing

        End If

    Next



End Sub

this is dgvdata table, it is linked to my sql server db

this is dgvalert table, any values from latest row in dgvdata that meets the condition as in comparevalues() will be tabulated here.

this is dgvsettings table, the limit conditions are all set in here.

so here is what i'm trying to do, although some of you might be able to interpret from the code given above. After filling up the dgvData with my sql data table, i'd like to compare the values in each columns of the latest row as according to the condition set in the comparevalues() sub. ie. if a value in, lets say column pH, exceeds the value limit set in the dgvSettings, then it will then added into the dgvAlert table.

but the problem is, when i run the code, those within the range set in the dgvSettings are still added into the dgvAlert. and most of them are taken as exceeded the limit when it should be still in the range limit. i've been cracking my head since the past few days trying to get it right. Your help is much appreciated. Thank you.

You are writing it wrong.

You have to convert those strings to actual numbers first if you want to compare them.

Public Sub comparevalues()

For z= 2 To dgvData.ColumnCount - 1

    Dim Cell1 as Double = CDbl(dgvData(z,0).Value.ToString)

    Dim Cell2 as Double = CDbl(dgvSettings(2,z-2).Value.ToString)

    Dim Cell3 as Double = CDbl(dgvSettings(1,z-2).Value.ToString)



    If Cell1  > Cell2 Then

        MsgBox("Value Exceed Maximum Limit")

        dgvAlert.Rows.Add(False, dgvData(1,0).Value.ToString, dgvData.Columns(z).HeaderText.ToString(), dgvData(z,0).Value.ToString, "Unacknowledged", dgvSettings(3,z-2).Value.ToString)

    ElseIf Cell1  < Cell3 Then

        MsgBox("Value Below Minimum Limit")

        dgvAlert.Rows.Add(False, dgvData(1,0).Value.ToString, dgvData.Columns(z).HeaderText.ToString(), dgvData(z,0).Value.ToString, "Unacknowledged", dgvSettings(3,z-2).Value.ToString)

    Else

        'in range, do nothing

    End If

Next

End Sub

Try the following to see why comparing strings with < and > does not work for your case.

Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        Dim x As String = "7".ToString

        Dim y As String = "10".ToString

        If x > y Then

            MessageBox.Show("7 is greater than 10")

        ElseIf x < y Then

            MessageBox.Show("10 is greater than 7")

        End If

End Sub

Get rid of the .ToString