xuesheng3.aspx.cs

学生网上选课系统,实现了学生的在线选课和教师课程的上传

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
    string datetime6 = "";
    SqlConnection conn;
    protected void Page_Load(object sender, EventArgs e)
    {
        string myconn = System.Configuration.ConfigurationManager.AppSettings["ConnectionString"];
        conn = new SqlConnection(myconn);
        if (!this.IsPostBack)
        {
            BindGrid();

        }
    }
    public void Data_Page(object sender, GridViewPageEventArgs e)
    {
        try
        {
            GridView1.PageIndex = e.NewPageIndex;
            DataBind();
        }
        catch { }
    }
    protected void BindGrid()
    {
        string id = Request.QueryString["departid"];
        string sql = "select cource.departid,cource.courceid,cource.courcetime,cource.courceaddress,teacher.teaid,cource.courcename,teacher.teaname,depart.departname,cource.courcerenshu,cource.renshu from cource,teacher,depart where cource.teaid=teacher.teaid and cource.departid=depart.departid and cource.departid='" + id + "' ";
        DataSet myds = new DataSet();
        SqlDataAdapter myda = new SqlDataAdapter(sql, conn);
        myda.Fill(myds);
        GridView1.DataSource = myds;
        GridView1.DataBind();
    }
    protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "select")
        {
            int index = Convert.ToInt32(e.CommandArgument);
            DataKey key = GridView1.DataKeys[index];
            string courceID = GridView1.DataKeys[index].Values[0].ToString().Trim();
            string teaID = GridView1.DataKeys[index].Values[1].ToString().Trim();
            string userName = Session["userName"].ToString();
            //计算选课门数
            string mysql1 = "select count(stuID) as num from elect Where stuID='" + userName + "'";
            SqlCommand cm1 = new SqlCommand(mysql1, conn);
            conn.Open();
            SqlDataReader dr1 = cm1.ExecuteReader();
            dr1.Read();
            int num = Convert.ToInt32(dr1["num"]);
            dr1.Close();
            conn.Close();
            //取出可选修课程的门数
            string mysql22 = "select glxkms from guanlixuanke";
            SqlCommand cm22 = new SqlCommand(mysql22, conn);
            conn.Open();
            SqlDataReader dr22 = cm22.ExecuteReader();
            dr22.Read();
            int n = Convert.ToInt32(dr22["glxkms"]);
            dr22.Close();
            conn.Close();
            //计算已选人数
            string mysql11 = "select * from cource Where courceID='" + courceID + "'";
            SqlCommand cm11 = new SqlCommand(mysql11, conn);
            conn.Open();
            SqlDataReader dr11 = cm11.ExecuteReader();
            dr11.Read();
            int csum = Convert.ToInt32(dr11["renshu"]);
            int climit = Convert.ToInt32(dr11["courcerenshu"]);
            dr11.Close();
            conn.Close();

            //选课满人
            if (csum < climit)
            {
                //先判断该学生的选课门数是否少于3门
                if (num < n)
                {
                    //验证该学生是否重复选了同一门课程


                    string mysql2 = "select * from elect Where stuID='" + userName + "' and courceID='" + courceID + "'";
                    SqlCommand cm2 = new SqlCommand(mysql2, conn);
                    conn.Open();
                    SqlDataReader dr2 = cm2.ExecuteReader();

                    //该学生没有重复选同一门课程，执行选课操作
                    if (!dr2.Read())
                    {
                        dr2.Close();
                        conn.Close();
                        string mysql6 = "select Cource.courcetime from Cource where CourceID='" + courceID + "'";
                        SqlCommand cm6 = new SqlCommand(mysql6, conn);
                        conn.Open();
                        SqlDataReader dr6 = cm6.ExecuteReader();
                        if (dr6.Read())
                        {
                            datetime6 = dr6["courcetime"].ToString();
                        }
                        conn.Close();
                        string mysql5 = "select * from elect,Cource,student where elect.courceID=Cource.courceID and elect.stuID=student.stuID and cource.courcetime='" + datetime6 + "' and elect.stuID='" + userName + "'";
                        SqlCommand cm5 = new SqlCommand(mysql5, conn);
                        conn.Open();
                        SqlDataReader dr5 = cm5.ExecuteReader();
                        if (!dr5.Read())
                        {
                            conn.Close();
                            conn.Open();
                            string mysql3 = "insert into Elect(stuID,courceID,teaID) values('" + userName + "','" + courceID + "','" + teaID + "')";

                            SqlCommand cm3 = new SqlCommand(mysql3, conn);
                            cm3.ExecuteNonQuery();

                            //选修人数加1
                            string mysql4 = "update cource set renshu=renshu+1 where courceID='" + courceID + "'";
                            SqlCommand cm4 = new SqlCommand(mysql4, conn);
                            cm4.ExecuteNonQuery();
                            Response.Write("<script>alert('选修成功。')</script>");


                            BindGrid();
                            conn.Close();

                        }
                        else
                        {
                            Response.Write("<script>alert('与你已选课程时间冲突,请选择其他课程!')</script>");
                            return;

                        }
                    }

                   //该学生重复选了同一门课程
                    else
                    {
                        Response.Write("<script>alert('你已经选修了这门课程，不能重复再选。')</script>");
                        return;
                    }
                    dr2.Close();
                    
                }
                else
                {
                    Response.Write("<script>alert('你已经超过了限选门数，我不能再选！')</script>");

                }
            }
            else
            {
                Response.Write("<script>alert('选课人数已满,请选择其他课程！')</script>");
                //dr1.Close();
                //cn1.Close();
            }



        }
    }
}