Login form cant connect to database - database

Question

I cannot connect to my database, i receive message "invalid user or password " even if the password is correct, what should i do anyone any idea or my code is wrong here are all my code for login form/
here is my code
Imports System.Data.SqlClient
Public Class LoginForm
Private Sub UsersBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles UsersBindingNavigatorSaveItem.Click
Me.Validate()
Me.UsersBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.DataSet1)
End Sub
Private Sub LoginForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'DataSet1.users' table. You can move, or remove it, as needed.
Me.UsersTableAdapter.Fill(Me.DataSet1.users)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim connection As New SqlConnection("Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database_topdent.mdf;Integrated Security=True")
Dim command As New SqlCommand("Select * from users where User = #user and Password = #password ", connection)
command.Parameters.Add("#user", SqlDbType.VarChar).Value = UserTextBox.Text
command.Parameters.Add("#password", SqlDbType.VarChar).Value = PasswordTextBox.Text
Dim adapter As New SqlDataAdapter(command)
Dim table As New DataTable()
adapter.Fill(table)
If table.Rows.Count() <= 0 Then
MessageBox.Show("username or textbox invalid")
Else
Form1.Show()
Me.Hide()
End If
End If
End Sub
End Class

Answer 1

This is so confusing.
You need to check for the username and password, not just count the rows. And that table.rows.count "<=0" ? makes no sense to me.
I can see where you were going with it, but its wrong. And the question itself is not clarified enough. But assuming this is a login form. Try this>
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1_Click
Dim connection As New SqlConnection("Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database_topdent.mdf;Integrated Security=True")
Dim command As New SqlCommand("Select * from [users] where [User] = #1 and [Password] = #2 ", connection)
connection.Open()
command.Parameters.AddWithValue("#1", UserTextBox.Text)
command.Parameters.AddWithValue("#2", PasswordTextBox.Text)
Using dr As SqlDataReader = command.ExecuteReader
Dim userFound As Boolean = False
Dim Name As String = ""
While dr.Read
userFound = True
Name = dr("User").ToString
End While
If userFound = True Then
MsgBox("Yes!")
ElseIf userFound = False Then
MsgBox("nay")
End If
End Using
connection.close()
End Sub
Just make sure your columns are set to vchar. I'm not able to test it, but it should work.
First you need to open the connection. Then you need to read the data in your database with the reader. then, if username and password is found, present a msg or whatever you want.
I'm sure there are better ways to do this, but here I am playing a quick good samaritan.
UPDATE #With permissions
1. Add another column named "Permissions"
2. Create a Module.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1_Click
Dim connection As New SqlConnection("Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database_topdent.mdf;Integrated Security=True")
Dim command As New SqlCommand("Select * from [users] where [User] = #1 and [Password] = #2 ", connection)
connection.Open()
command.Parameters.AddWithValue("#1", UserTextBox.Text)
command.Parameters.AddWithValue("#2", PasswordTextBox.Text)
Using dr As SqlDataReader = command.ExecuteReader
Dim userFound As Boolean = False
While dr.Read
userFound = True
User1 = dr("User").ToString
Permissions = dr("Permissions").ToString
End While
If userFound = True Then
MsgBox("Yes!")
ElseIf userFound = False Then
MsgBox("nay")
End If
End Using
connection.close()
End Sub
A module
Module Module1
Public User1 As String
Public Permissions As String
End Module
And then call stuff in your forms...
For example in your main form or wherever, if you have 2 buttons on load form you can do
If Permissions = "admin" then
Button1.enabled = true
else if Permissions = "user" then
msgbox(fu)
end if

Answer 2

Hello here are my code for login with admin/user it works, but know i want to make permission example when user is logged in not have full access , but the admin is full access..
Here are all my codes for ' Login_Form '
Imports System.Data.SqlClient
Module Module1
Public User1 As String
Public Permissions As String
End Module
Public Class LoginForm
Private Sub UsersBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles UsersBindingNavigatorSaveItem.Click
Me.Validate()
Me.UsersBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.DataSet1)
End Sub
Private Sub LoginForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'DataSet1.users' table. You can move, or remove it, as needed.
Me.UsersTableAdapter.Fill(Me.DataSet1.users)
If Permissions = "admin" Then
Button1.Enabled = True
ElseIf Permissions = "user" Then
Form1.RaportetToolStripMenuItem.Visible = False
End If
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs)
End Sub
Private Sub Button4_Click(sender As Object, e As EventArgs)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim connection As New SqlConnection("Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database_topdent.mdf;Integrated Security=True")
Dim command As New SqlCommand("Select * from [Table_login] where [Username] = #1 and [Password] = #2 ", connection)
connection.Open()
command.Parameters.AddWithValue("#1", UserTextBox.Text)
command.Parameters.AddWithValue("#2", PasswordTextBox.Text)
Using dr As SqlDataReader = command.ExecuteReader
Dim userFound As Boolean = False
Dim Name As String = ""
While dr.Read
userFound = True
Name = dr("Username").ToString
End While
If userFound = True Then
Form1.Show()
ElseIf userFound = False Then
MsgBox("Username or password is wrong!!!!!! ")
End If
End Using
connection.Close()
If Permissions = "user1" Then
Form1.RaportetToolStripMenuItem.Visible = False
End If
End Sub
End Class