SQL calculation within VB.Net not working - sql

Question

This is a pre-assignment for a class I'm in. Supposed to be pretty simple and act as a warm-up, but I can't get it working. Basically the code is bringing in a test database and performing a calculation. In this case I'm trying to find the highest average batting average in a set of baseball players.
So my end result should be the name of the player with the highest batting average, or a few players if they are tied for the highest average.
Here is the code:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim dt As DataTable = New DataTable()
Dim connStr As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Baseball.accdb"
Dim sqlStr As String = "SELECT * FROM Players"
Dim dataAdapter As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(sqlStr, connStr)
dataAdapter.Fill(dt)
dataAdapter.Dispose()
Dim average, pastAverage, highestAverage As Double
For i As Integer = 0 To dt.Rows.Count - 1
average = CDbl(dt.Rows(i)("hits/atBats"))
If average > pastAverage Then
highestAverage = average
End If
pastAverage = average
Next
For i As Integer = 0 To dt.Rows.Count - 1
If dt.Rows(i)("hits/atBats") = highestAverage Then
lstBoxHighest.Items.Add(dt.Rows(i)("name"))
End If
Next
End Sub
End Class
The debugger won't go past the "average = Cdbl(dt.Rows(i)("hits/atBats"))" line in the first For Loop. Can I not do calculations like that in the loop? I am sure the column titles (hits and atBats are correct)
The database looks like this in case you were wondering:
name Team atBats hits
Derek Jeter New York Yankees 511 158
Joe Mauer Minnesota Twins 545 174
etc...
Thanks!

Answer 1

you are missing some object refs:
average = CDbl(dt.Rows(i).item("hits") / dt.Rows(i).item("atBats"))
and like that for the rest of them. VB needs an dt.Rows(i) reference because those are 2 different columns. With "hits/atBats", it cant know those are individual columns.
Shorthand, but kind of masks that they are different cols/items is like you had it:
average = CDbl(dt.Rows(i)("hits") / dt.Rows(i)("atBats"))

Answer 2

Disclaimer: it's not a direct answer to the question.
Instead of pulling all the data to the client and then using two loops to find a name you can do all calculations on db-side and grab only needed rows and columns (in your case just name) with a query that may look like
SELECT name
FROM Players
WHERE atBats / hits =
(
SELECT MAX(atBats / hits)
FROM Players
)
Output:
| NAME |
|-------------|
| Derek Jeter |