Im new to visual basic and im currently working on a log in form linked to mysql...i have a code for the log in button but it only gives me an error.This is the code
Private Sub LogIn_btn_Click(sender As Object, e As EventArgs) Handles LogIn_btn.Click
dbconn = New MySqlConnection()
dbconn = New MySqlConnection("Data Source=localhost;user id=root;password=root;database=oeas") With {
.ConnectionString = "Data Source=localhost;user id=root;password=root;database=oeas"
}
sqlcmd = New MySqlCommand()
Try
dbconn.Open()
Const V As String = "select * From oeas.users where User_Name = '" & Pass_txtbx.Text&"' and Password ='" & UserN_txtbx.Text& "' "
query = V
sqlcmd = New MySqlCommand(query, dbconn)
dbrd = sqlcmd.ExecuteReader
Dim count As Integer
count = 0
While dbrd.Read
count = count + 1
End While
If count = 1 Then
MessageBox.Show("username and password are correct")
Profile_form.Show()
Me.Hide()
ElseIf count > 1 Then
MessageBox.Show("username and password are duplicate")
Else
MessageBox.Show("username and password are not correct")
End If
Catch ex As MySqlException
MsgBox("Connection Error: " & ex.Message.ToString)
End Try
End Sub
what might be wrong?
Related
I'm making a tool to help a company with there staff holiday (staff holiday calculator)
I connected myself by vb and its connection to the database but I can't get any result
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim conn As New api()
Dim adapter As New MySqlDataAdapter()
Dim table As New DataTable()
Dim command As New MySqlCommand("SELECT `Full_Name`, `Job`, `Free_Days` FROM `Holiday` WHERE `Username`= '#name'", conn.getConnection())
command.Parameters.Add("#name", MySqlDbType.VarChar).Value = api.id
Try
conn.getConnection.Open()
adapter.SelectCommand = command
adapter.Fill(table)
Dim sqlReader As MySqlDataReader = command.ExecuteReader()
While sqlReader.Read()
namee = sqlReader("Full_Name").ToString()
job = sqlReader("Job").ToString()
days = sqlReader("Free_Days").ToString()
MsgBox(sqlReader("Full_Name").ToString())
End While
Label2.Text = "Name : " + namee
Label3.Text = "Job : " + job
Label8.Text = "Holiday Free Days : " & days
Catch ex As MySql.Data.MySqlClient.MySqlException
MsgBox(ex.Message)
End Try
End Sub
I didn't get any MsgBox and there is no error and the label text didn't change
I don't have MySQL, but based on MSSQL try something like this:
Dim namee, job, days As String
Dim commandText As String = "SELECT `Full_Name`, `Job`, `Free_Days` FROM `Holiday` WHERE `Username`= '#name'"
Dim conn As New api()
Using adapter As New MySqlDataAdapter(commandText, conn.getConnection())
adapter.SelectCommand.Parameters.Add("#name", MySqlDbType.VarChar).Value = api.id
Dim table As New DataTable()
adapter.Fill(table)
If table.Rows.Count = 0 Then
MessageBox.Show("No rows found", "ERROR")
Else
With table(0)
namee = .Item("Full_Name")
job = .Item("Job")
days = .Item("Free_Days")
End With
End If
End Using
In the above I want it to give me the value of "ID" of the "Username" associated with it.
Here is the command I tried
Dim Query2 = String.Format("SELECT ID FROM account WHERE character = " & UsernameTextBox.Text & " ")
Command = New MySqlCommand(Query2, mydbcon)
Dim idtest = reader.Read.ToString
MsgBox(idtest)
however it is returning "false" what am I doing wrong?
Here is the entire code that I am working on:
Try
mydbcon.Open()
Dim Query As String
Query = String.Format("SELECT * FROM account WHERE username = '{0}' AND password = '{1}'", Me.UsernameTextBox.Text.Trim(), Me.PasswordTextBox.Text.Trim())
Dim Command = New MySqlCommand(Query, mydbcon)
reader = Command.ExecuteReader
Dim count As Integer
count = 0
While reader.Read
count = count + 1
End While
If count = 1 Then
MessageBox.Show("Username and password are correct")
Query = String.Format("SELECT username AS ID FROM account WHERE character = " & UsernameTextBox.Text & " ")
Command = New MySqlCommand(Query, mydbcon)
My.Settings.LoginID = reader.Read
MsgBox(My.Settings.LoginID)
ElseIf count > 1 Then
MessageBox.Show("Username and password are duplicate")
Else
MessageBox.Show("Username and password are wrong")
End If
mydbcon.Close()
Catch ex As MySqlException
MessageBox.Show(ex.Message)
Finally
mydbcon.Dispose()
End Try
Use ID as alias (so select username AS anyNameYouWantToAssignToIt):
Dim Query2 = String.Format("SELECT username AS ID FROM account WHERE character = " & UsernameTextBox.Text & " ")
What am I doing wrong here? I get an error:
incorrect syntax near =
on this line of code:
Dim SqlDataReader As SqlClient.SqlDataReader = SQLCommad.ExecuteReader()
My code:
Dim Username = TUserName.Text
Dim Password = TPassword.Text
Dim SqlConnection = New SqlClient.SqlConnection(My.Settings.DBConnection.ToString)
Dim SQLCommand = New SqlClient.SqlCommand("select * from " + My.Settings.TableName.ToString + "Where EmpID = " + Username, SqlConnection)
SqlConnection.Open()
Dim SqlDataReader As SqlClient.SqlDataReader = SQLCommand.ExecuteReader
While (SqlDataReader.Read)
If Username = SqlDataReader(1).ToString And Password = SqlDataReader(20).ToString Then
If eEncrypt(Username, Password) Then
MsgBox("You are NOT logged in")
Else
MsgBox("You are logged in")
End If
End If
End While
SqlConnection.Close()
This should work, see how a parammeter is added
Dim Username = TUserName.Text
Dim Password = TPassword.Text
Dim SqlConnection = New SqlClient.SqlConnection(My.Settings.DBConnection.ToString)
Dim SQLCommand = New SqlClient.SqlCommand("select * from " + My.Settings.TableName.ToString + "Where EmpID = #Username", SqlConnection)
SQLCommand.Parameters.AddWithValue("#Username", Username)
SqlConnection.Open()
Dim SqlDataReader As SqlClient.SqlDataReader = SQLCommand.ExecuteReader()
While (SqlDataReader.Read)
If Username = SqlDataReader(1).ToString And Password = SqlDataReader(20).ToString Then
If eEncrypt(Username, Password) Then
MsgBox("You are NOT logged in")
Else
MsgBox("You are logged in")
End If
End If
End While
SqlConnection.Close()
you miss parenthesis
Dim SqlDataReader As SqlClient.SqlDataReader = SQLCommad.ExecuteReader()
This line of code
Dim SQLCommand = New SqlClient.SqlCommand("select * from " + My.Settings.TableName.ToString + "Where EmpID = " + Username, SqlConnection)
should be
Dim SQLCommand = New SqlClient.SqlCommand("select * from " + My.Settings.TableName.ToString + "Where EmpID = '" + Username + "'", SqlConnection)
posted from mobile.
I have queried my MySql database and data is stored in a dataset named Search Events(I have checked this and it works)
However when i try to pass this data into a datagridview and then ultimately my array it doesn't seem to work :( The problem seems to be that no data is being passed from Search Events into Table
Any ideas??
Dim Table As New DataGridView
Table.DataSource = SearchEvents.Tables("Event ID")
Dim EventID(Table.Rows.Count - 1) As String
For i = 0 To 12
EventID(i) = Table.Rows(0).Cells(i).Value
Next
'Try the following function
Public Sub getuserlist()
Dim con As New MySqlConnection(ConnectionString)
Try
If con.State <> ConnectionState.Open Then
con.Open()
End If
Dim selecttaxinv = "SELECT * FROM user_tb WHERE user_status = 'Active' ORDER BY date_registered DESC"
Dim myCommand As New MySqlCommand(selecttaxinv, con)
Dim dr As MySqlDataReader
dr = myCommand.ExecuteReader()
yourdatagridview.Rows.Clear()
Dim b = 1
While dr.Read()
Dim fullname As String = dr("fname") & " " & dr("mname") & " " & dr("lname")
Dim row As String() = New String() {dr("user_id"), b, fullname, dr("fname"), dr("date_registered")}
yourdatagridview.Rows.Add(row) 'print list
b += 1
End While
dr.Close()
If con.State = ConnectionState.Open Then
con.Close()
End If
Catch ex As Exception
MessageBox.Show(ex.Message, "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Try
End Sub
FYI, I have tables Authority and Users. In my Users table, it has 4 columns namely: user_id, username, password, authority_id and in Authority table, it has 2 columns: authority_id, authority_level.
My login form asks user for their username and password. Upon giving the correct parameters, it should validate the user if it is an admin = 1, nurse = 2, or doctor = 2.
Here's what I've tried so far:
Private Sub btnLogin_Click(sender As System.Object, e As System.EventArgs) Handles btnLogin.Click
If txtUsername.Text = "" Or txtPassword.Text = "" Then
MsgBox("Enter UserName and Password Moron")
Else
'SQL Query To Get The Details
Dim myAdapter As New MySqlDataAdapter
Dim sqlquerry = "Select * From users where username = '" + txtUsername.Text + "' And password= '" + txtPassword.Text + "'"
Dim myCommand As New MySqlCommand()
myCommand.Connection = SQLConnection
myCommand.CommandText = sqlquerry
'Starting The Query
myAdapter.SelectCommand = myCommand
Dim mydata As MySqlDataReader
mydata = myCommand.ExecuteReader
'To check the Username and password and to validate the login a
If mydata.HasRows = 0 Then
MsgBox("Invalid Login")
Else
MsgBox("Welcome " + txtUsername.Text + "!")
If authority Then
frmMain.Show()
Else
frmMainNurse.Show()
End If
Me.Hide()
End If
End If
End Sub
Notice that I haven't added something in this line:
If authority Then
I don't know how to do it in vb.net. So if anyone knows how to do this, I'll greatly appreciate your help. Thanks.
Do this in your else part
Else
Dim authorityid = 0
While mydata.Read()
authorityid = mydata.GetInt32("authority_id")
End While
MsgBox("Welcome " + txtUsername.Text + "!")
If authorityid = 1 Then
frmMain.Show()
Else
frmMainNurse.Show()
End If
Me.Hide()
End If