利用oledbconnection连接sql数据库的问题

[jiez]

如题，做了一个简单的登录界面，输入正确的用户名和密码，明明数据库中存在这样的用户名和密码，可是还是进入“ MsgBox("用户名不存在或者密码错误", 0 + 48, "提示")”，经检测好像是没有查出数据来，怎么回事呢？
另外，该定义的都定义了，没有出现编译错误。
代码如下：
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

If TextBox1.Text = "" Then
MsgBox("请输入用户名", MsgBoxStyle.Information, "警告")
Exit Sub
End If

If TextBox2.Text = "" Then
MsgBox("请输入密码", MsgBoxStyle.Information, "警告")
Exit Sub
End If

Dim myconnection As OleDb.OleDbConnection
Dim strconnet As String = "Provider=SQLOLEDB;Data Source=(Local);Initial Catalog=chapter1;user id=sa;password=;"
myconnection = New System.Data.OleDb.OleDbConnection(strconnet)
myconnection.Open()
Dim str As String = "select * from aa where name=' & TextBox1.Text& ' and pwd=' & TextBox2.Text& '"


mycommand = New OleDbCommand(str, myconnection)


mydatareader = mycommand.ExecuteReader
Dim a As String = mydatareader.GetString(0)

TextBox3.Text = a


If mydatareader.Read = False Then
MsgBox("用户名不存在或者密码错误", 0 + 48, "提示")
Else
Me.Hide()
Dim f2 As New Form2
f2.Show()
End If
mydatareader.Close()
myconnection.Close()



End Sub

[wuyq11]

Using conn As New SqlConnection("")
Dim cmd1 As New SqlCommand("select * from tb where username='" &txt.Text & "'", conn)
'或sqlparameter
conn.Open()
Using dr As SqlDataReader = cmd1.ExecuteReader()
If dr.Read() Then
End If
End Using
End Using

[jiez]

用oledbconnection和sqlconnection不是一样吗？有什么区别
问题在这儿吗？

[jiez]

找到问题所在了