student.vb

来自「系统概要: 本系统采用VB.NET开发. 开发平台:Windows XP P」· VB 代码 · 共 123 行

'
'    Copyright(C)2006,济南大学材料科学与工程学院
'    All right reserved.
'
'    文件名称:Student.vb
'    文件标识:
'    摘    要:学生类
'
'    当前版本:1.0.0
'    作    者:梁  海
'    完成日期:2006-11-29
'
'    取代版本:
'    原作者  :
'    完成日期:
'
'    修改历史:
'

Imports System.Data.SqlClient

Public Class Student
    Inherits StudentInfo

    Private oSql As SqlDataAccess
    Private oReader As SqlDataReader
    Private strSql As String
    '  
    '    构造方法
    '  
    Public Sub New()

        MyBase.New()
        oSql = New SqlDataAccess

    End Sub
    '  
    '    构造方法
    '    摘    要:参数:ID是学生的学号
    '  
    Public Sub New(ByVal ID As String)

        MyBase.New()
        oSql = New SqlDataAccess
        '如果该学号的学生存在
        If Exist(ID) Then
            '构造查询字符串,根据学号查询出该学生的基本信息
            strSql = "Select * From vStudent Where (SID='" & ID & "')"
            oSql.Sql = strSql
            oReader = oSql.DataReader()
            If oReader.Read() Then
                SID = CType(oReader.Item("SID"), String)
                Name = CType(oReader.Item("Name"), String)
                Team = CType(oReader.Item("Team"), String)
                Mayor = CType(oReader.Item("Mayor"), String)
                Department = CType(oReader.Item("Department"), String)
                CardID = CType(oReader.Item("CardID"), String)
                If CType(oReader.Item("Name"), Boolean) Then
                    Sex = "M"
                Else
                    Sex = "F"
                End If
            End If
            oReader.Close()
        End If

    End Sub

    '  
    '    方法名称:Grade(ByVal CardID As String) As String
    '    摘    要:根据学号,身份证号(密码)查询成绩
    '             参数:CardID 是学生的身份证号
    '  
    Public Function Grade(ByVal CardID As String) As String

        Dim o As Object
        Dim CID As String

        '对CardID时行特殊字符过滤
        CID = FilterText(CardID)

        '构造SQL查询字符串
        Me.strSql = "Select Grade From vGrade Where SID='" & SID & _
                     "' AND CardID='" & CID & "')"

        '设置数据库查询对象属性
        oSql.Sql = Me.strSql

        '查询数据库,并返回查询成绩结果
        '不存在符合条件的记录:返回Sorry!...
        '存在:返回学生成绩
        o = oSql.ExecuteScalar()
        If o Is Nothing Then
            Return "Sorry! Error Password or Grade is Not Exist."
        Else
            Return Convert.ToString(o)
        End If

    End Function

    '  
    '    方法名称:Exist(ByVal ID As String) As Boolean
    '    摘    要:查询该学号的学生是否存在
    '             参数:ID 是学生的学号
    '  
    Public Function Exist(ByVal SID As String) As Boolean

        Dim strSql As String
        strSql = "Select count(*) From vStudent Where (SID='" & SID & "')"
        oSql.Sql = strSql
        If CType(oSql.ExecuteScalar(), Integer) > 0 Then
            Return True
        Else
            Return False
        End If

    End Function


End Class