scorem.cs

精通网络应用系统开发 光盘 该书是人民邮电出版社出版的

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections.Generic;
using System.Data.Linq;
/// <summary>
/// Summary description for ScoreM
/// </summary>
public class ScoreM
{
	public ScoreM()
	{
	}
    public IQueryable<Score> GetScoreByGrade(int nGradeID)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        //首先获取该年级的学生
        IQueryable<Score> scores;
        try
        {
             scores = db.Scores.Where(s => s.Student.Class.GradeID == nGradeID);
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }

        ///返回从数据库获取的结果
        return (scores);
    }

    public IQueryable<Score> GetScoreByClass(int nClassID)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        IQueryable<Score> scores;
        try
        {
            scores = db.Scores.Where(s => s.Student.Class.ClassID==nClassID);
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }

        ///返回从数据库获取的结果
        return (scores);
    }

    public IQueryable<Score> GetScoreByStudent(int nStudentID)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        IQueryable<Score> scores;
        try
        {
            scores = db.Scores.Where(s => s.StudentID==nStudentID);
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }

        ///返回从数据库获取的结果
        return (scores);
    }

    public IQueryable<Score> GetScoreByCourse(int nCourseID)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        IQueryable<Score> scores;

        try
        {
            scores = db.Scores.Where(s => s.CourseID==nCourseID);
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }

        ///返回从数据库获取的结果
        return (scores);
    }

    public Score GetScoreByStudentCourse(int nStudentID, int nCourseID)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        Score score;
        try
        {
            score = db.Scores.Where(s => s.StudentID == nStudentID && s.CourseID == nCourseID).First();
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }

        ///返回从数据库获取的结果
        return (score);
    }

    public void AddScore(int nStudentID, int nCourseID, decimal dMark)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        try
        {
            Score sco = new Score { StudentID = nStudentID, CourseID = nCourseID, Mark = dMark };
            db.Scores.InsertOnSubmit(sco);
            db.SubmitChanges();
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }
    }

    public void UpdateScore(int nStudentID, int nCourseID, decimal dMark)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        try
        {
            Score sco = db.Scores.Where(s => s.StudentID == nStudentID && s.CourseID == nCourseID).First();
            sco.Mark = dMark;
            db.SubmitChanges();
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }
    }

    public void CheckScore(int nStudentID, int nCourseID)
    {
        DataClassesDataContext db = new DataClassesDataContext();
        try
        {
            Score sco = db.Scores.Where(s => s.StudentID == nStudentID && s.CourseID == nCourseID).First();
            sco.Flag = 1;
            db.SubmitChanges();
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }
    }

    public void DeleteScore(int nScoreID)
    {
        DataClassesDataContext db = new DataClassesDataContext();

        try
        {
            Score sco = db.Scores.Where(s => s.ScoreID == nScoreID).First();
            db.Scores.DeleteOnSubmit(sco);
            db.SubmitChanges();
        }
        catch (Exception ex)
        {
            ///抛出执行数据库异常
            throw new Exception(ex.Message, ex);
        }
    }
}