为什么数据未插入SQL数据库

Question

我正在尝试将多个textboxes和datatable复选框值插入SQL database。但是，我的数据未插入数据库中。按照下面的代码，弹出“将数据插入数据库时​​出错！” 。谁能帮助我确定为什么会这样？

private void button1_Click(object sender, EventArgs e)
    {

        var result = this.dataGridView1[1, 0].Value; //checkbox at row 1
        var result2 = this.dataGridView1[1, 1].Value;//checkbox at row 2
        var result3 = this.dataGridView1[1, 2].Value;//
        var result4 = this.dataGridView1[1, 3].Value;

        string mainconn = ConfigurationManager.ConnectionStrings["Test.Properties.Settings.TransitiondayConnectionString"].ConnectionString;
            SqlConnection sqlconn = new SqlConnection(mainconn);

            string sqlquery = "INSERT INTO [dbo].[Infotable] (Busnumber,Busmodel,Dt1check1,Dt1check2,Dt1check3,Dt1check4)";
            sqlquery+= "values(@Busnumber,@Busmodel,@Dt1check1, @Dt1check2, @Dt1check3, @Dt1check4)";


            SqlCommand sqlcomm = new SqlCommand(sqlquery, sqlconn);

            sqlcomm.CommandType = CommandType.Text;
            sqlcomm.Parameters.Add("@Busnumber", SqlDbType.Text).Value =label1.ToString();
            sqlcomm.Parameters.Add("@Busmodel", SqlDbType.Text).Value = label7.ToString();
            sqlcomm.Parameters.Add("@Dt1check1", SqlDbType.Bit).Value = result;
            sqlcomm.Parameters.Add("@Dt1check2", SqlDbType.Bit).Value = result2;
            sqlcomm.Parameters.Add("@Dt1check3", SqlDbType.Bit).Value = result3;
            sqlcomm.Parameters.Add("@Dt1check4", SqlDbType.Bit).Value = result4;

            sqlconn.Open();
            int test = sqlcomm.ExecuteNonQuery();

            if (test != 0)
            {
                MessageBox.Show("Error inserting data into Database!");

            }
            else
            {
                MessageBox.Show("OK!");
            }

            sqlconn.Close();

    }