select client

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace GestionDeSctock1.Forms
{
    public partial class choseclient : MetroFramework.Forms.MetroForm
    {
        public choseclient()
        {
            InitializeComponent();

        }
        SqlConnection cn = new SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=gestion2;Integrated Security=True;");
        SqlDataAdapter da;
        DataTable dt = new DataTable();

        private void choseclient_Load(object sender, EventArgs e)
        {
            dt.Clear();
            da = new SqlDataAdapter(@"SELECT [id]
                                              ,[Nom_client] as [Nom du client]
                                              ,[Address]
                                              ,[N_telephone] as [N° Téléphone]
                                              ,[N_registre_commerce] as [N° Registre commerce]
                                              ,[N_article] as [N° Article]
                                          FROM [dbo].[client]", cn);
            da.Fill(dt);
            this.metroGrid1.DataSource = dt;

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            dt.Clear();
            da = new SqlDataAdapter(@"SELECT [id]
                                              ,[Nom_client] as [Nom du client]
                                              ,[Address]
                                              ,[N_telephone] as [N° Téléphone]
                                              ,[N_registre_commerce] as [N° Registre commerce]
                                              ,[N_article] as [N° Article]
                                          FROM [dbo].[client] WHERE [Nom_client] + [Address] + [N_telephone] + [N_registre_commerce] LIKE '%" + textBox1.Text + "%' ", cn);
            da.Fill(dt);
            this.metroGrid1.DataSource = dt;
        }

        private void metroGrid1_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            textBox2.Text = metroGrid1.CurrentRow.Cells[1].Value.ToString();
        }

        private void addbtn_Click(object sender, EventArgs e)
        {
            Forms.addvente ad = new addvente(textBox2.Text);
            this.Close();
        }
    }
}