Ms-access "Great Than" or equal query - vb.net

Question

I have an Ms-access DB that contain 40 students and I want to find students who are at least 18 years old.
I tried to use this code but it doesn't work!
Try
DataGridView1.Rows.Clear()
Dim dt As DataTable = New DBConnect().selectdata(String.Format("SELECT ID, Name FROM Students where Age > %{0}%", FlatTextBox8.Text))
For i As Integer = 0 To dt.Rows.Count - 1
DataGridView1.Rows.Add(i + 1, dt.Rows(i)(0), dt.Rows(i)(1))
Next
dt.Dispose()
dt = Nothing
Catch ex As Exception
End Try
How can I do this?

Answer 1

Name is a reserved word, so try with:
String.Format("SELECT ID, [Name] FROM Students where Age > {0}", FlatTextBox8.Text))
That said, use parameters.

Answer 2

It's better to use parametrized query in order to avoid sql injection.
This little function will fill and return a DataTable with the value you are looking at!
Private Function GetData() As System.Data.DataTable
Dim dt As New DataTable
Dim sqlCmd As String = "SELECT ID, Name FROM Students where Age > #Age"
Using myConnection As New SqlConnection(your_connection_string)
myConnection.Open()
Using myDataAdapter As New SqlDataAdapter(sqlCmd, myConnection)
myDataAdapter.SelectCommand.Parameters.Add("#Age", SqlDbType.Int) 'Change the type if your DB Table has another type
myDataAdapter.SelectCommand.Parameters("#Age").Value = Convert.ToInt16(FlatTextBox8.Text) 'Change the type if your DB Table has another type
myDataAdapter.Fill(dt)
End Using
myConnection.Close()
End Using
Return dt
End Function
Now it's time to call it inside your code:
Try
DataGridView1.Rows.Clear()
Dim dt As DataTable = GetData()
For i As Integer = 0 To dt.Rows.Count - 1
DataGridView1.Rows.Add(i + 1, dt.Rows(i)(0), dt.Rows(i)(1))
Next
dt.Dispose()
dt = Nothing
Catch ex As Exception
MsgBox(ex.Message)
Err.Clear
End Try
As you can notice, I also added a MsgBox() that will show you the error message if an exception is thrown. I found this very helpful while debugging.