st_grade_manage.aspx.cs

学生管理系统。C#开发。偏重与数据库的应用。

        {
            st_comm.ExecuteNonQuery();
            st_lbl_note.Text = "编辑成功";
            st_dtg_grade.EditItemIndex = -1;
        }
        catch (SqlException)
        {
            st_lbl_note.Text = "编辑失败";
            st_lbl_note.Style["color"] = "red";
        }
        st_comm.Connection.Close();
        ST_BindGrid();

    }

    public void DataGrid_delete(object sender, DataGridCommandEventArgs e)
    {

        string st_sqlstr = "delete from ST_student_course where ST_ID=@id";
        SqlCommand st_comm = new SqlCommand(st_sqlstr, st_conn);
        st_comm.Parameters.Add(new SqlParameter("@id", SqlDbType.Char, 10));
        st_comm.Parameters["@id"].Value = st_dtg_grade.DataKeys[(int)e.Item.ItemIndex];
        st_comm.Connection.Open();
        try
        {
            st_comm.ExecuteNonQuery();
            st_lbl_note.Text = "删除成功";

        }
        catch (SqlException)
        {
            st_lbl_note.Text = "删除失败";
            st_lbl_note.Style["color"] = "red";
        }
        st_comm.Connection.Close();
        ST_BindGrid();
    }

    protected void st_btn_count_Click(object sender, System.EventArgs e)
    {
        if (st_ddl_stat.SelectedItem.Value == "系别")
        {

            if (st_ddl_content.SelectedItem.Text == "总人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_department='" + st_tbx_area.Text + "' ";
            }
            else if (st_ddl_content.SelectedItem.Text == "优秀人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_department='" + st_tbx_area.Text + "'and ST_Student_grade>=85 ";
            }
            else if (st_ddl_content.SelectedItem.Text == "不及格人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_department='" + st_tbx_area.Text + "'and ST_Student_grade<60 ";
            }
            else
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=class.ST_Class_id and ST_class.ST_Class_department='" + st_tbx_area.Text + "' ";
            }
        }
        else if (st_ddl_stat.SelectedItem.Value == "学院")
        {
            if (st_ddl_content.SelectedItem.Text == "总人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_college='" + st_tbx_area.Text + "' ";
            }
            else if (st_ddl_content.SelectedItem.Text == "优秀人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_college='" + st_tbx_area.Text + "'and ST_Student_grade>=85 ";
            }
            else if (st_ddl_content.SelectedItem.Text == "不及格人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_college='" + st_tbx_area.Text + "'and ST_Student_grade<60 ";
            }
            else
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade) from ST_student_course,ST_student,ST_class where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "'and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid=ST_class.ST_Class_id and ST_class.ST_Class_college='" + st_tbx_area.Text + "' ";
            }


        }
        else if (st_ddl_stat.SelectedItem.Value == "班级")
        {
            if (st_ddl_content.SelectedItem.Text == "总人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "' and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid='" + st_tbx_area.Text + "'";
            }
            else if (st_ddl_content.SelectedItem.Text == "优秀人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "' and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid='" + st_tbx_area.Text + "'and ST_Student_grade>=85";
            }
            else if (st_ddl_content.SelectedItem.Text == "不及格人数")
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade),COUNT(*) from ST_student_course,ST_student where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "' and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid='" + st_tbx_area.Text + "'and ST_Student_grade<60";
            }
            else
            {
                st_sqlstr = "select AVG(ST_Student_grade),MAX(ST_Student_grade) from ST_student_course,ST_student where ST_Course_id='" + st_tbx_classid.Text + "' and ST_student_course.ST_Course_year='" + st_tbx_year.Text + "' and ST_student_course.ST_Student_id=ST_student.ST_Student_id and ST_student.ST_Student_classid='" + st_tbx_area.Text + "'";
            }


        }
        SqlCommand st_comm = new SqlCommand(st_sqlstr, st_conn);
        st_conn.Open();
        SqlDataReader dr = st_comm.ExecuteReader();
        if (dr.Read())
        {
            if (st_ddl_content.SelectedItem.Text == "平均分")
            {
                st_lbl_average.Visible = true;
                st_lbl_average.Text = "平均分为：" + dr[0].ToString();
            }
            else if (st_ddl_content.SelectedItem.Text == "最高分")
            {
                st_lbl_high.Visible = true;
                st_lbl_high.Text = "最高分为：" + dr[1].ToString();
            }
            else if (st_ddl_content.SelectedItem.Text == "总人数")
            {
                st_lbl_all.Visible = true;
                st_lbl_all.Text = "总人数为：" + dr[2].ToString();
            }
            else if (st_ddl_content.SelectedItem.Text == "优秀人数")
            {
                st_lbl_a.Visible = true;
                st_lbl_a.Text = "优秀人数为：" + dr[2].ToString();
            }
            else if (st_ddl_content.SelectedItem.Text == "不及格人数")
            {
                st_lbl_unpass.Visible = true;
                st_lbl_unpass.Text = "不及格人数为：" + dr[2].ToString();
            }
            else
            {
                st_lbl_note.Text = "无此信息";
            }
            st_conn.Close();
        }


    }
    protected void st_lbtn_addgrade_Click(object sender, EventArgs e)
    {
        Response.Redirect("ST_addgrade.aspx");
    }
}