c# 数据库更新问题

        private void AdminPlacement_Load(object sender, EventArgs e)
        {
            pobjconn.Open();
            SqlCommand pobjcom = new SqlCommand();
            pobjcom.CommandText = "select CourseName,ElectivesID from View_1";
            pobjcom.Connection = pobjconn;
            pobjcom.ExecuteNonQuery();
            SqlDataAdapter pobjdat = new SqlDataAdapter(pobjcom);
            pobjdat.Fill(table);
            comboBox1.DataSource = table;
            comboBox1.DisplayMember = "CourseName";
            comboBox1.ValueMember = "ElectivesID";
            pobjconn.Close();
        }

        private void button1_Click_1(object sender, EventArgs e)
        {
            table1.Clear();
            pobjconn.Open();
            SqlCommand pobjcom = new SqlCommand();
            pobjcom.CommandText = "select CourseName as 选修课,TeacherName as 教师,StuName as 学生 from AdminPlacement where ElectivesID=@ElectivesID";
            pobjcom.Parameters.Add("@ElectivesID", SqlDbType.Int).Value = comboBox1.SelectedValue;
            pobjcom.Connection = pobjconn;
            pobjcom.ExecuteNonQuery();
            SqlDataAdapter pobjdat1 = new SqlDataAdapter(pobjcom);
            pobjdat1.Fill(table1);
            dataGridView1.DataSource = table1;
            dataGridView1.AllowUserToAddRows = false;
            for (int j = 0; j < dataGridView1.Columns.Count; j++)
                dataGridView1.Columns[j].SortMode = DataGridViewColumnSortMode.NotSortable;
            pobjconn.Close();
            textBox1.Text = dataGridView1.Rows.Count.ToString();
        }

        private void button2_Click(object sender, EventArgs e) 
 
        {
            if (int.Parse(textBox1.Text.ToString()) > 30 && int.Parse(textBox1.Text.ToString()) < 50)
            {
                textBox2.Text = "1100";
                Class.Class1 = textBox2.Text;
                pobjconn.Open();
                SqlCommand pobjcom = new SqlCommand();
                pobjcom.CommandText = "update ElectiveDetails set Class=1100";

                pobjcom.Connection = pobjconn;
                pobjcom.ExecuteNonQuery();
                pobjconn.Close();
                MessageBox.Show("班级生成成功！");
            }
            else if (int.Parse(textBox1.Text.ToString()) < 30)
                MessageBox.Show("人数不够不予开班！");
          
        }

入门新手想问下，我这样在生成班级的时候，只能生成“1100”，如何修改代码，可以循环把班级加上去，就是第二次生成的班级是1101..1102..1103 这样。还有就是 代码有累赘的地方，希望大家可以指导下。
数据库 c# textbox table object
[解决办法]
private void AdminPlacement_Load(object sender, EventArgs e)
{
pobjconn.Open();
SqlCommand pobjcom = new SqlCommand();
pobjcom.CommandText = "select CourseName,ElectivesID from View_1";
pobjcom.Connection = pobjconn;
pobjcom.ExecuteNonQuery();
SqlDataAdapter pobjdat = new SqlDataAdapter(pobjcom);
pobjdat.Fill(table);
comboBox1.DataSource = table;
comboBox1.DisplayMember = "CourseName";
comboBox1.ValueMember = "ElectivesID";

pobjconn.Close();
}

private void button1_Click_1(object sender, EventArgs e)
{
table1.Clear();
pobjconn.Open();
SqlCommand pobjcom = new SqlCommand();
pobjcom.CommandText = "select CourseName as 选修课,TeacherName as 教师,StuName as 学生 from AdminPlacement where ElectivesID=@ElectivesID";
pobjcom.Parameters.Add("@ElectivesID", SqlDbType.Int).Value = comboBox1.SelectedValue;
pobjcom.Connection = pobjconn;
pobjcom.ExecuteNonQuery();
SqlDataAdapter pobjdat1 = new SqlDataAdapter(pobjcom);
pobjdat1.Fill(table1);
dataGridView1.DataSource = table1;
dataGridView1.AllowUserToAddRows = false;
for (int j = 0; j < dataGridView1.Columns.Count; j++)
dataGridView1.Columns[j].SortMode = DataGridViewColumnSortMode.NotSortable;
pobjconn.Close();
textBox1.Text = dataGridView1.Rows.Count.ToString();
}

private int classNum = 1100;
private void button2_Click(object sender, EventArgs e)
{
if (int.Parse(textBox1.Text.ToString()) > 30 && int.Parse(textBox1.Text.ToString()) < 50)
{
textBox2.Text = classNum.ToString();
Class.Class1 = textBox2.Text;
pobjconn.Open();
SqlCommand pobjcom = new SqlCommand();
pobjcom.CommandText = "update ElectiveDetails set Class=1100";

pobjcom.Connection = pobjconn;

pobjcom.ExecuteNonQuery();
pobjconn.Close();
MessageBox.Show("班级生成成功！");
}
else if (int.Parse(textBox1.Text.ToString()) < 30)
MessageBox.Show("人数不够不予开班！");

}
红色代码是多余的，因为使用SqlDataAdapter的时候不需要显示的开闭连接，也不需要ExecuteNonQuery，否则就执行2次了。

绿色代码是新更正的，定义一个字段记录就可以累加了。