private SqlConnection sqlConnection = null;
        private SqlDataAdapter sqlDataAdapter = null;
        private SqlCommandBuilder sqlCommandBuilder = null;
        private DataTable dataTable = null;
        private BindingSource bindingSource = null;
        private String selectQueryString = null;
        string nametable;
        public Form1()
        {
            InitializeComponent();
 
        }
 
        public void FillGrid()
        {
            sqlConnection = new SqlConnection(@"Data Source=dp;Initial Catalog=arsisbd;Integrated Security=True");
 
            if (nametable == "Trains1")
            {
                selectQueryString = "тут sql запрос";
            }
 
 
            sqlConnection.Open();
            sqlDataAdapter = new SqlDataAdapter(selectQueryString, sqlConnection);
            sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);
            dataTable = new DataTable();
            sqlDataAdapter.Fill(dataTable);
            bindingSource = new BindingSource();
            bindingSource.DataSource = dataTable;
 
 
            dataGridView1.DataSource = bindingSource;
            dataGridView1.Columns[0].Visible = true;
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            dataGridView1.DataSource = null;
            if ((checkBox1.Checked == true) )
            {
                    nametable = "Trains1"; FillGrid();
            }
        }

datagridview1.Dock = DockStyle.Fill;