string person_ID = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0].Value.ToString();
                string person_name = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[1].Value.ToString();
                string person_age = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[2].Value.ToString();
                string person_sex = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[3].Value.ToString();
//然后将数据更新到数据库、
                SqlConnection coon = new SqlConnection(connectionstring);
                coon.Open();
                SqlCommand cmd = new SqlCommand("update 酒店人员 set 姓名 =@name, 年龄 =@age, 性别 =@sex where 工作编号 =@id,coon);
                cmd.Parameters.AddWithValue("@name",person_name );
                cmd.Parameters.AddWithValue("@age",person_age );
                cmd.Parameters.AddWithValue("@sex",person_sex );
                cmd.Parameters.AddWithValue("@id",person_ID);
                SqlDataReader dr = cmd.ExecuteReader();
                coon.Close();
                MessageBox.Show("修改数据成功！");

------解决方案--------------------
插入行：
C# code

string insertStr = "insert into 学生信息(学号,姓名,性别,出生日期,民族,所属班级,家庭地址) values ('','','','','','','')";
            SqlCommand insert_com = new SqlCommand(insertStr, conn);
            if (insert_com.ExecuteNonQuery() > 0)
            {
                MessageBox.Show("插入新数据成功","成功提示");
            }