Обновление БД MySql

Finally
            conn.Open()
            Dim Query1 As String
            DogovorShow()
            Summary()
            Query1 = "UPDATE dlamysql.Dolzniki SET Ostatok = (( Select SummaDogovora from dlamysql.Dolzniki where Dogovor =  '" & TextBox2.Text & "' ) - '" & TextBox1.Text & "' ) where Dogovor= '" & TextBox2.Text & "' "
            COMMAND = New MySqlCommand(Query1, conn)
            conn.Close()
            conn.Dispose()
            End Try

 Private Sub Button_UpdateDolzniki_Click(sender As Object, e As EventArgs) Handles Button_UpdateDolzniki.Click
 
        Dim conn As New MySqlConnection
        Dim DatabaseName As String = "dlamysql"
        Dim server As String = "*****"
        Dim userName As String = "*****"
        Dim password As String = "****"
        Dim COMMAND As MySqlCommand
        Dim SDA As New MySqlDataAdapter
        Dim dbDataSet As New DataTable
        Dim bSource As New BindingSource
 
 
        Button_adddoor.Visible = True
        conn.ConnectionString = String.Format("server={0}; user id={1}; password={2}; database={3}; pooling=false", server, userName, password, DatabaseName)
 
        'For i = 1 To 15
 
 
   
        Counter = Counter + 1
 
        Try
            conn.Open()
            Dim Query As String
 
 
            Query = "Select Dogovor, Summa from dlamysql.Kassa where Dogovor = any (select Dogovor from Dolzniki where id= '" & Counter & "' and pogasen= 'no' )"
            COMMAND = New MySqlCommand(Query, conn)
            SDA.SelectCommand = COMMAND
            dbDataSet.Clear()
            SDA.Fill(dbDataSet)
            bSource.DataSource = dbDataSet
            ShowSumma.DataSource = bSource
            SDA.Update(dbDataSet)
            conn.Close()
        Catch ex As MySqlException
            MessageBox.Show(ex.Message)
        Finally
            conn.Open()
            Dim Query1 As String
            DogovorShow()
            Summary()
            Query1 = "UPDATE dlamysql.Dolzniki SET Ostatok = (( Select SummaDogovora from dlamysql.Dolzniki where Dogovor =  '" & TextBox2.Text & "' ) - '" & TextBox1.Text & "' ) where Dogovor= '" & TextBox2.Text & "' "
            COMMAND = New MySqlCommand(Query1, conn)
            conn.Close()
            conn.Dispose()
            End Try
    
 
 
 
    End Sub
 
 
 
Sub DogovorShow()
        Dim s As Integer
        s = ShowSumma.Rows(0).Cells(0).Value
        TextBox2.Text = s
    End Sub
    Sub Summary()
 
        Dim x As Integer
        For line As Integer = 0 To ShowSumma.RowCount - 1
            x = x + ShowSumma.Rows(line).Cells(1).Value
        Next
        TextBox1.Text = x
 
 
    End Sub

COMMAND = New MySqlCommand(Query1, conn)
COMMAND.ExecuteNonQuery()    
conn.Close()

 conn.Dispose

conn.Close