students.cs

大二做的课程设计。一个学生信息管理系统

using System;
using System.Data;
using System.Data.SqlClient;

namespace StudentLibrary.Business
{
    using StudentLibrary.DataAccess;

    public class Students
    {
        private DataBaseOperate cDbObject = null;
        private bool bConn = false;


        public Students()
        {
            cDbObject = new DataBaseOperate();
            bConn = false;
        }


        public Students(DataBaseOperate dbOperate)
        {
            cDbObject = dbOperate;
            bConn = true;
        }

        public bool UpdateStudent(
            int iStudentId,
            string sStudentNo,
            string sStudentName,
            DateTime dBirthday,
            int iGender,
            int iClassId,
            string sRemark)
        {
            string sSql =
                "update Student"
                + " set"
                + " StudentNo = '" + sStudentNo + "'"
                + ",StudentName = '" + sStudentName + "'"
                + ",Birthday = '" + dBirthday.ToString() + "'"
                + ",Gender = " + iGender.ToString()
                + ",ClassId = " + iClassId.ToString()
                + ",Remark = '" + sRemark + "'"
                + " where StudentId = " + iStudentId.ToString();

            try
            {
                cDbObject.Execute(sSql);
            }
            catch (Exception e)
            {
                throw (e);
            }
            return true;
        }

        public bool InsertStudent(
            DateTime dBirthday,
            int iGender,
            int iClassId,
            int iStatus,
            string sStudentNO,
            string sStudentName,
            string sRemark)
        {
            string sSql =
                "insert Student("
                + " StudentNO"
                + ",StudentName"
                + ",Gender"
                + ",Birthday"
                + ",ClassId"
                + ",Status"
                + ",Remark)"
                + " values("
                + "'" + sStudentNO + "'"
                + ",'" + sStudentName + "'"
                + "," + iGender.ToString()
                + ",'" + dBirthday.ToString() + "'"
                + "," + iClassId.ToString()
                + "," + iStatus.ToString()
                + ",'" + sRemark + "'"
                + ")";

            try
            {
                cDbObject.Execute(sSql);
            }
            catch (Exception e)
            {
                throw e;
            }
            return true;
        }

        public DataSet SelectStudent(
            int iStudentId,
            string sStudentName,
            string sStudentNo,
            int iClassId)
        {

            string sSql =
                "select	a.*"
                + ",b.ClassName"
                + " from Student a"
                + ",Class b"
                + " where a.ClassId = b.ClassId";

            if (iStudentId != -1)
            {
                sSql += " and a.StudentId = " + iStudentId;
            }
            if (sStudentName != "")
            {
                sSql += " and a.StudentName = '" + sStudentName + "'";
            }
            if (sStudentNo != "")
            {
                sSql += " and a.StudentNO = '" + sStudentNo + "'";
            }
            if (iClassId != -1)
            {
                sSql += " and a.ClassId = " + iClassId.ToString();
            }

            DataSet dataSet = new DataSet();
            try
            {
                dataSet = cDbObject.Search(sSql, "Student");
            }
            catch (Exception e)
            {
                throw (new ApplicationException("操作数据库发生错误：" + e.Message));
            }
            return dataSet;
        }

        public bool DeleteStudent(
            int iStudentId,
            int iClassId)
        {
            string sSql =
                "delete student where 1 = 1";
            if (iStudentId != -1)
            {
                sSql += " and StudentId = " + iStudentId.ToString();
            }
            if (iClassId != -1)
            {
                sSql += " and ClassId = " + iClassId.ToString();
            }

            try
            {
                cDbObject.Execute(sSql);
            }
            catch (Exception e)
            {
                throw (new ApplicationException("操作数据库发生错误：" + e.Message));
            }
            return true;
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(true);
        }

        public virtual void Dispose(bool disposing)
        {
            if (!disposing)
            {
                return;
            }

            if (!bConn)
            {
                cDbObject.CloseDataBase();
            }
        }


    }
}