sqldatareader的应用

[vb]代码库

Public Sub connect()
       Dim pass As Boolean
       pass = False
       Dim conn As New SqlConnection
       Dim rs As New SqlCommand
       Dim dataread As SqlDataReader
       Dim constr As String
       'Dim i As Integer
       Dim sql As String
       constr = "server=PC-201105311336\SQLEXPRESS;Uid=sa;Pwd=123456;Database=jiaxiaoai" '无源连接
       conn = New SqlConnection(constr)
       conn.Open()
       sql = "select * from sysname"
       rs = New SqlCommand(sql, conn)
       dataread = rs.ExecuteReader()

       While (dataread.Read)
           If dataread(0).ToString = usertext.Text And dataread(1).ToString = passwordtext.Text Then
               pass = True
           End If
       End While

       If pass = True Then
           Me.Hide()
           显示学生信息.Show()
       Else
           MsgBox("用户名或密码错误")
       End If

   End Sub