datagridview 查询数据库数据

 private void btnsearch_Click(object sender, EventArgs e)
        {
            if (txtSearch.Text != "")
            {
                this.dataGridView1.DataSource = null;
                string str = @"Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=Test;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False";
                SqlConnection sqlConnection = new SqlConnection(str);
                sqlConnection.Open();
                string sql = String.Format("select * from Student where Name='{0}'", txtSearch.Text);
                SqlDataAdapter dataAdapter = new SqlDataAdapter(sql, sqlConnection);
                DataSet dataSet = new DataSet();
                dataAdapter.Fill(dataSet);
                this.dataGridView1.DataSource = dataSet.Tables[].DefaultView;
                sqlConnection.Close();
            }
            else
            {
                load();
            }

        }