vb.net login with sqlite - vb.net

Question

im trying to create a login form in vb.net with SQLite with this code
Imports System.Data.SQLite
Public Class frmLogin
Private Sub btnlogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnlogin.Click
Dim table As DataTable = Nothing
Dim da As New SQLiteDataAdapter("Select * from user_tbl where username='" & txtuser.Text & "'and pass_id='" & txtpass.Text & "'", myconn)
Try
If txtuser.Text = "" And txtpass.Text = "" Then
MessageBox.Show("Please fill Username and Password", "Important", MessageBoxButtons.OK, MessageBoxIcon.Information)
txtuser.Focus()
Else
da.Fill(table)
If table.Rows.Count > 0 Then
frmMain.Show()
Me.Close()
Else
MessageBox.Show("login not successful")
End If
da.Dispose()
End If
Catch ex As Exception
MessageBox.Show(ex.ToString)
End Try
End Sub
Private Sub frmLogin_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ConnectME()
End Sub
End Class
but i keep getting an error at line 26 "da.fill(table)"
Here is what the error says:

Answer 1

Here are two lines of your code:
Dim table As DataTable = Nothing
da.Fill(table)
You have no code in between that assigns an object to that table variable. Why exactly are you surprised that there's an issue here? If I told you to fill a bag and then handed you no bag, how exactly would you go about filling it? You couldn't, because you can't fill a bag that doesn't exist, yet you expect your app to be able to fill a DataTable that doesn't exist.