Zitat:

Gebunden ist das ganze an meine MySQL-Datenbank ohne DataSet o.ä., weil ich da nicht durchgestiegen bin.

public Class DataAccess
	Protected _Connectionstring  As String
	public sub New(ByVal connectionstring as String)
		_Connectionstring = connectionstring
	End Sub
 
	Public Function GetDatabases() as DataTable
		Return ReadDataTable( "SHOW DATABASES" )
	End Function
 
	Public Function GetTables( databaseName as string) as DataTable
		ChangeDatabase( databaseName )
		Return ReadDataTable( "SHOW TABLES" )
	End Function
 
	Public Function ReadTable(tableName as string) as DataTable
		Return ReadDataTable( string.Format("SELECT * FROM {0}", tableName) )
	End Function
 
	Public Function WriteTable(tableName as string, dt as DataTable)
		Using adapter as new MySqlDataAdapter(string.Format("SELECT * FROM {0}", _
  tableName), _Connectionstring)
			Dim cb as new MySqlCommandBuilder(adapter)
			adapter.Update(dt)
		End Using
	End Function
 
	Public Sub ChangeDatabase(newDatabase as string)
		dim csb as new MySqlConnectionstringBuilder(_Connectionstring)
		csb.Database = newDatabase
		_Connectionstring = csb.ToString()
	End Sub
 
	public Function ReadDataTable(sql as string ) as DataTable
		Dim dt as new DataTable
		Using adapter as new MySqlDataAdapter(sql, _Connectionstring)
			adapter.Fill( dt )
		End Using
		Return dt
	End Function
end Class

Public Class OptionenForm
	Inherits System.Windows.Forms.Form
 
	Protected DAL as DataAccess
 
	public sub new()
		InitialiseComponents()
		Dim Connectionstring as string = String.Format("server={0};user id={1};" & _
  "password={2}; database=mysql", tb_server.Text, tb_user.Text, tb_passwd.Text)
		DAL = new DataAccess(Connectionstring)
	End Sub
	Private Sub cmd_connect_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles cmd_connect.Click
 
		Try
            Dim dt as DataTable = DAL.GetDatabases()
            cb_database.DisplayMember = dt.columns(0).ColumnName
			cb_database.DataSource = dt			
        Catch ex As MySqlException
            MessageBox.Show("Error connecting to the server: " + ex.Message)
        End Try
	End Sub
 
	Private Sub cb_database_SelectedIndexChanged(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles cb_database.SelectedIndexChanged
 
        Try
            Dim dt as DataTable = DAL.GetTables(cb_database.Text)
            cb_tables.DisplayMember = dt.columns(0).ColumnName
			cb_tables.DataSource = dt			
 
        Catch ex As SqlException
            MessageBox.Show("Failed to populate table list: " + ex.Message)
        Finally
            If Not reader Is Nothing Then reader.Close()
        End Try
    End Sub
 
 
	Private Sub cb_tables_SelectedIndexChanged(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles cb_tables.SelectedIndexChanged
		DasDataGridView.DataSource = DAL.ReadTable(cb_tables.Text)
    End Sub
 
End Class