Заполнение dataGridView из бд (firebird)

using System;
using System.Data;
using System.Linq;
using System.Windows.Forms;
using Dapper;
using FirebirdSql.Data.FirebirdClient;
namespace WindowsFormsApp4
{
    public partial class Form1 : Form
    {
        private FbConnectionStringBuilder csb = null;
        private FbConnection db = null;
        public Form1()
        {
            InitializeComponent();
          
        }  
        private void Form1_Load(object sender, EventArgs e)
        {
            csb = new FbConnectionStringBuilder();
            csb.DataSource = "localhost";
            csb.Port = 3050;
            csb.Database = @"C:\735\SQL\aa.fdb";
            csb.UserID = "SYSDBA";
            csb.Password = "masterkey";
            csb.ServerType = FbServerType.Default;
 
            db = new FbConnection(csb.ToString());
            db.Open();
 
        }
 private void button2_Click(object sender, EventArgs e)
        {
            FbCommand cmd = new FbCommand("select * from client", db);
            FbDataAdapter adapter = new FbDataAdapter(cmd);
            DataTable dt = new DataTable();
            adapter.Fill(dt);
            dataGridView1.DataSource = dt;
        }
    }
}