No row at position 0

[Freiderich92]

Hi guys, i'm kinda stuck again and i know that you geniuses will probably be able to help me out

ok so i've been creating a program in VB that connects to a Microsoft database, and up until now, the program has been displaying the information fine. however, all i get now is the error message "No row at position 0" whenever it tries to display almost anything.

I am baffled as i have 3 forms that work and are programmed exactly the same way and only 1 works fine :/

HEELLLPP!

        MaxRows = ds.Tables("TTDB").Rows.Count

        Do

            ListBox1.Items(inc) = ds.Tables("TTDB").Rows(inc).Item("TeacherName") - error message from this segment

            inc = inc + 1

        Loop Until inc = MaxRows

[jmcilhinney]

The error message speaks for itself. There is no row at position 0 so you cannot get the row at position 0. Your Do loop should be using a pre-condition to allow for that rather than a post-condition:

MaxRows = ds.Tables("TTDB").Rows.Count
 
        Do Until inc = MaxRows
 
            ListBox1.Items(inc) = ds.Tables("TTDB").Rows(inc).Item("TeacherName") - error message from this segment
 
            inc = inc + 1
 
        Loop

Now the condition will be tested BEFORE each iteration so you'll never enter the loop if there aren't any rows.

That said, you really shouldn't be using a Do loop there anyway. a Do loop should be used for a condition not related to counting. If you can count the iterations then a For loop is far more suitable than a Do loop:

Dim rows As DataRowCollection = ds.Tables("TTDB").Rows
 
For i As Integer = 0 To rows.Count - 1
    ListBox1.Items(i) =rows(i)("TeacherName")
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