Question

嘿所有人我是asp.net的新手，我想从数据库中选择数据并将数据存储在VB中的DataTable而不是C＃中，但我似乎无法理解如何连接。任何人都可以帮我尝试连接到访问数据库吗？我很迷茫，已经好几天了。如果不是它的确定。

感谢您的阅读。

布伦特

Public Function CheckUser(ByVal p_strUserNAME As String, ByVal p_Password As String) As Boolean
    Dim blnAdminUser As Boolean = False

    Dim SQLQuery As String = "SELECT Username, Password FROM HomelessUsers WHERE Username = " & p_strUserNAME & " AND Password = " & p_Password

    Dim MDBConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\HomelessCapstone\HomelessCapstone\HomelessCapstone\APP_Data\Homeless.accdb;Persist Security Info=True"
    Dim ds As New DataSet
    Dim cnn As OleDbConnection = New OleDbConnection(MDBConnectionString)

    cnn.Open()

    Dim cmd As New OleDbCommand(SQLQuery, cnn)
    Dim da As New OleDbDataAdapter(cmd)
    da.Fill(ds, "HomelessUsers")
    cnn.Close()


    'Dim DatatableTest As DataTable = ds.Tables("HomelessUsers")
    'Dim Row As DataRow = Nothing
    'Dim Item(2) As String


    'For Each Row In DatatableTest.Rows
    'item()
    ' Next



    Return blnAdminUser
End Function

Answer 1

基本上，有两种方法可以解决它。一种是使用ADO（访问数据库对象），它具有一个非常有用的向导，可以帮助您将访问数据库连接到程序并为控件设置数据源，或者您可以使用System.Data.OLEDb（我更喜欢这个，因为它让我可以更好地控制我的系统）

Dim accessconn As New  _
System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data source=" & pathofAccessFile)
    Try
        accessconn.Open()
        MsgBox("Access succesfully connected")
        accessconn.Close()
        Return 0
    Catch ex As Exception
        accessconn.Close()
        MsgBox("There is something wrong with the path provided.")
    Return 1


    End Try

你需要了解使用OLEDb类，所以这里有一些东西可以帮到你。 http://msdn.microsoft.com/en-us/library/System.Data.OleDb(v=vs.110).aspx

记下OLEDbCommand（执行SQL字符串），OLEDbDataAdapter（将数据从DB转换为Datagridview）和OLEDbDataReader（我用它来从数据库中选择数据）。

也许是为了帮助您更好地理解您的问题，以下是我如何使用DataReader类的示例：

  Public Sub AccesstoGridd(ByVal utos As String, ByVal pathh As String, ByVal gridd As DataGridView, ByVal ngalan As String)
    Dim accessconn As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data source=" & pathh)
    Try


        Dim sqlutos As New System.Data.OleDb.OleDbCommand(utos, accessconn)
        Dim idcounter As Integer = 0

        accessconn.Open()
        Dim reader As System.Data.OleDb.OleDbDataReader
        reader = sqlutos.ExecuteReader
        While reader.Read
            idcounter = idcounter + 1
            gridd.Rows.Add(idcounter, reader(0), reader(1), reader(2), reader(3), reader(4), reader(5), ngalan)
        End While
        reader.Close()


        accessconn.Close()
    Catch ex As Exception
        accessconn.Close()
        MsgBox("There is something wrong with the Access file selected." & vbNewLine & ex.ToString, MsgBoxStyle.Exclamation, "MDB file unrecognized.")
    End Try

End Sub

如何选择和插入ASP.NET VB中的Microsoft Access数据库（accdb）

1 个答案: