For loop skipping rows in DataSet

Question

Hi!

My Application uses For...Next loops to read a spreadsheet into a DataSet and then display information from it based on the results of search conditions (search term and a date range).

I'm having a problem with the data where, if I run a search that should return the first 400 rows in the spreadsheet, I'm only getting around 200 results. I know the search should return the 400 rows because I checked it in the spreadsheet before running the search.

I think my problem might be caused by my date comparisons. I think the problem might be that I'm comparing String value, so if anyone can show me a more efficient way of comparing dates, then that'll be great.

Here's my code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    If ListBox1.Items.Count <> 0 Then : ListBox1.Items.Clear() : End If
    Dim j As Integer = 0
    If TextBox1.Text.Length = 4 Then
        For i As Integer = 0 To CallData.Tables(0).Rows.Count - 1
            'MsgBox(CallData.Tables(0).Rows(i)(2) & " - FROM( " & DateTimePicker1.ToString & " ) TO( " & DateTimePicker2.ToString & " )")
            If CallData.Tables(0).Rows(i)(3).ToString = TextBox1.Text _
            And CallData.Tables(0).Rows(i)(2).ToString > DateTimePicker1.Value.ToString _
            And CallData.Tables(0).Rows(i)(2).ToString < DateTimePicker2.Value.ToString Then
                ListBox1.BeginUpdate()
                ListBox1.Items.Add(CallData.Tables(0).Rows(i)(2).ToString)
                ListBox1.EndUpdate()
                j = j + 1
            End If
        Next

        Label1.Text = j & " records found."
    End If
End Sub

Answer 1

When you compare strings to each other it doesn't have anything to do with dates, it compares them alphabetically. You can just cast the object from the row to a date and then compare.

Change:

CallData.Tables(0).Rows(i)(2).ToString > DateTimePicker1.Value.ToString
CallData.Tables(0).Rows(i)(2).ToString < DateTimePicker2.Value.ToString 

to:

CType(CallData.Tables(0).Rows(i)(2), DateTime) > DateTimePicker1.Value
CType(CallData.Tables(0).Rows(i)(2), DateTime) < DateTimePicker2.Value

Btw, I'm no vb expert but I guess this code should do the trick :-)