Cross-thread operation not valid: Control textbox accessed from a thread other than the thread it was created on. vb.net
Sub autocompletepayee()
Dim cmd2 As New Odbc.OdbcCommand
Dim dr As Odbc.OdbcDataReader
Dim myquery As String
myquery = "select payee from tbrequest"
cmd2.CommandText = myquery
cmd2.Connection = con
dr = cmd2.ExecuteReader
While dr.Read
txtPayee.AutoCompleteCustomSource.Add(dr.GetString(0)) 'this is the line where the error prompt
End While
dr.Close()
This should work, though it might be shorter if more were known about where the code was located
Dim cmd2 As New Odbc.OdbcCommand
Dim dr As Odbc.OdbcDataReader
Dim myquery As String
myquery = "select payee from tbrequest"
cmd2.CommandText = myquery
cmd2.Connection = con
dr = cmd2.ExecuteReader
While dr.Read
If txtPayee.InvokeRequired Then
txtPayee.Invoke(Sub()
txtPayee.AutoCompleteCustomSource.Add(dr.GetString(0)) 'this is the line where the error prompt
End Sub)
Else
txtPayee.AutoCompleteCustomSource.Add(dr.GetString(0)) 'this is the line where the error prompt
End If
End While
dr.Close()
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
please, can anybody explain why this code is not working?
Connection to mysql is made via mysql odbc driver (latest).
Parameter in Select command is not recognized.
I also tried to replace #param1 in Select command:
Select product_id from product where model = ?
code still not working.
Sub Main()
Dim DBCONT As New Odbc.OdbcConnection
Dim strConn As String = "DSN=MyDSN"
DBCONT.ConnectionString = strConn
DBCONT.Open()
Dim cmd As New Odbc.OdbcCommand
With cmd
.CommandText = "SELECT product_id FROM products WHERE model = #param"
.Connection = DBCONT
End With
Dim param1 As Odbc.OdbcParameter
param1 = cmd.CreateParameter()
With param1
.ParameterName = "#param"
.OdbcType = Odbc.OdbcType.VarChar
.Size = 30
.Value = "TESTVALUE"
End With
Dim reader As Odbc.OdbcDataReader
reader = cmd.ExecuteReader
Console.WriteLine(cmd.CommandText.ToString)
'this line displays "Select product_id from products where model = #param"
'instead of "Select product_id from products where model = "TESTVALUE"..
'WHY??
While reader.Read
Console.WriteLine(reader(0))
Console.WriteLine()
End While
Console.ReadLine()
DBCONT.Close()
reader = Nothing
cmd = Nothing
End Sub
Where it says:
".CommandText = "SELECT product_id FROM products WHERE model = #param"
Change it to:
".CommandText = "SELECT product_id FROM products WHERE model = '#param'"
(I've put ' ' around the #param, keep in mind this is different to the " " that is surrounding this)
I'm not 100% sure but I'll post this as an answer anyway because I think it's correct:
Dim cmd As New Odbc.OdbcCommand
With cmd
.CommandText = "SELECT product_id FROM products WHERE model = :param"
.Connection = DBCONT
End With
Dim param1 As Odbc.OdbcParameter
param1 = cmd.CreateParameter()
With param1
.ParameterName = "param"
.OdbcType = Odbc.OdbcType.VarChar
.Size = 30
.Value = "TESTVALUE"
End With
Thanks for your help. This code is already working:
Sub Main()
Dim DBCONT As New Odbc.OdbcConnection
Dim strConn As String = "DSN=MyDSN"
DBCONT.ConnectionString = strConn
DBCONT.Open()
Dim cmd As New Odbc.OdbcCommand
With cmd
.CommandText = "SELECT product_id FROM products WHERE model LIKE ?"
//it seems it is important to add paramater right after commandtext
.Parameters.Add("#param", OdbcType.VarChar).Value = "%" + "TESTVALUE" + "%"
.Connection = DBCONT
End With
Dim reader As Odbc.OdbcDataReader
reader = cmd.ExecuteReader
Console.WriteLine(cmd.CommandText.ToString)
//it should display SELECT product_id FROM products WHERE model LIKE ?
While reader.Read
Console.WriteLine(reader(0))
Console.WriteLine()
End While
Console.ReadLine()
DBCONT.Close()
reader = Nothing
cmd = Nothing
End Sub
I have this problem:
MySQL server version for the right syntax to use near 'where no ='count'' at line 1
This is my code:
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
MysqlConn = New MySqlConnection
MysqlConn.ConnectionString = "server=localhost;userid=root;password=;database=penjara"
Dim Reader As MySqlDataReader
MysqlConn.Open()
Dim query As String
Dim spath As String
Dim count As Integer = 0
Dim mysound As Media.SoundPlayer
Dim cmd As MySqlCommand
Dim rdr As MySqlDataReader
query = "Select * from penjara.info"
Command = New MySqlCommand(query, MysqlConn)
Reader = Command.ExecuteReader
While Reader.Read
Reader.Close()
count = count + 1
query = "Select penjara.info where no ='count'"
cmd = New MySqlCommand(query, MysqlConn)
rdr = cmd.ExecuteReader
End While
End Sub
How can I solve this error?
Try this:
query = "Select * from penjara.info where no = '" & count & "'"
This will pass in the value of variable count. However, note that this is an unsafe approach since concatenating to form queries makes your app vulnerable to SQL Injection. Instead you should use parameterised queries.
Dim connStr As String = "server=localhost;userid=root;password=;database=penjara"
Using MySqlConn As New MySqlConnection(connStr)
Using cmd As New MySqlCommand()
With cmd
.Connection = MySqlConn
.CommandText = "Select * from penjara.info where no = #count"
.CommandType = CommandType.Text
.Parameters.AddWithValue("#count", count)
End With
Try
MySql.Open()
rdr = cmd.ExecuteReader
Catch ex As Exception
<handle exception>
End Try
End Using
End Using
If I only add one query such as hostnameQuery the code works fine, as you can see I have tried to add multiple.
I've tried using + and & on the MySqlCommand but I get a syntax error returned.
Dim hostnameQuery As String = "SELECT `HOSTNAME` FROM `m1` WHERE 1"
Dim osQuery As String = "SELECT `OS` FROM `m1` WHERE 1"
Dim SQLConnection As New MySqlConnection(My.Settings.connStr)
Dim cmd As New MySqlCommand(hostnameQuery & osQuery, SQLConnection)
Try
SQLConnection.Open()
cmd.ExecuteNonQuery()
Dim reader As MySqlDataReader
reader = cmd.ExecuteReader
While reader.Read
main.Label64.Text = (reader.GetString(0))
main.Label65.Text = (reader.GetString(0))
End While
Catch ex As Exception
MsgBox(ex.Message.ToString)
Finally
SQLConnection.Close()
End Try
try:
Dim hostnameQuery As String = "SELECT `HOSTNAME` FROM `m1` WHERE 1 UNION ALL (SELECT `OS` FROM `m1` WHERE 1)";
or you why not (since you quering 1 table):
Dim hostnameQuery As String = "SELECT `HOSTNAME`,`OS` FROM `m1` WHERE 1 ";
.....
While reader.Read
main.Label64.Text = (reader.GetString(0))
main.Label65.Text = (reader.GetString(1))
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