vb.net - 使用 ms 访问数据库在 vb.net 中进行选择

Question

我想在我的表中选择一些数据并使用以下代码：

Public Class frmLogin
Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOK.Click
            Dim t As New DataTable
    Dim adapter As OleDbDataAdapter = New OleDbDataAdapter()
    Dim cmd As OleDbCommand
    Dim reader As OleDbDataReader = Nothing
    Dim tuser As String = txtUsername.Text

    Dim sql As String = "SELECT * FROM dosen WHERE nip=tuser"
    Try
        cmd = New OleDbCommand(sql, conn)
        reader = cmd.ExecuteReader()

        While reader.Read
            MessageBox.Show(reader.GetString(0).ToString & _
                            vbTab & vbTab & reader.GetString(1).ToString)
        End While
    Finally
        If reader IsNot Nothing Then reader.Close()
    End Try

End Sub

但是线路有误reader = cmd.ExecuteReader()。任何人都可以帮助我吗？

Answer 1

修改错误。代码应该是

Dim reader As OleDbDataReader ' no need for nothing
Dim adapter As New OleDbDataAdapter()
Dim sql As String = "SELECT * FROM dosen WHERE nip='" & tuser & "'"

tuser 是一个变量，而不是内容