ASP.Net/ADO.net Database/OleDbConnection — различия между версиями

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Версия 15:30, 26 мая 2010

Read data from OleDbConnection (VB.net)

<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.Oledb" %>
<script language="vb" runat="server">
Sub Page_Load()
  Dim strConnection as String = "Provider=Microsoft.Jet.OLEDB.4.0;"
    strConnection += "Data Source=Northwind.mdb"
    data_src.text = strConnection
  Dim strSQL as string = "SELECT FirstName, LastName FROM Employees"
  Dim strResultsHolder as string
  Dim objConnection as New OledbConnection(strConnection)
  Dim objCommand as New OledbCommand(strSQL, objConnection)
  Dim objDataReader as OledbDataReader
  try
    objConnection.Open()
    con_open.text="Connection opened successfully.<br />"
  objDataReader = objCommand.ExecuteREader()
  Do While objDataReader.Read()=True
    strResultsHolder +=objDataREader("FirstName")
    strResultsHolder +="&nbsp;"
    strResultsHolder +=objDataREader("LastName")
    strResultsHolder +="<br>"
  Loop
  objDataReader.Close()
    objConnection.Close()
    con_close.text="Connection closed.<br>"
  divListEmployees.innerHTML = strResultsHolder
  catch e as Exception
    con_open.text="Connection failed to open successfully.<br>"
    con_close.text=e.ToString()
  end try
end Sub
</script>
<html>
  <body>
  <h4>Reading data from the connection 
  <asp:label id="data_src" runat="server"/> with the DataReader object.</h4>
  <asp:label id="con_open" runat="server"/><br>
  <div id="divListEmployees" runat="server">list will go here</div>
  <asp:label id="con_close" runat="server"/><br>
  </body>
</html>



Reading data from the OleDbConnection in C#

<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<script Language="c#" runat="server">
  void Page_Load()
  {
    string strConnection = "Provider=Microsoft.Jet.OleDb.4.0;";
    strConnection += @"Data Source="+MapPath("EmployeeDatabase.mdb");
    data_src.Text = strConnection;
    string strSQL = "SELECT FirstName, LastName FROM Employee";
    DataSet objDataSet = new DataSet();
    OleDbConnection objConnection = new OleDbConnection(strConnection);
    OleDbDataAdapter objAdapter = new OleDbDataAdapter(strSQL, objConnection);
    objAdapter.Fill(objDataSet, "Employees");
    DataView objDataView = new DataView(objDataSet.Tables["Employees"]);
    dgNameList.DataSource=objDataView;
    dgNameList.DataBind();
  }
</script>
<html>
  <body>
  <h4>Reading data from the connection 
  <asp:label id="data_src" runat="server"/> to the DataGrid control.</h4>
  <asp:datagrid id="dgNameList" runat="server" /><br />
  </body>
</html>


<A href="http://www.nfex.ru/Code/ASPDownload/EmployeeDatabase.zip">EmployeeDatabase.zip( 10 k)</a>


Try to connect to access database through OleDbConnection (VB.net)

<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.Oledb" %>
<script language="VB" runat="server">
  Sub Page_Load()
    Dim strConnection as String = "Provider=Microsoft.Jet.OLEDB.4.0;"
    strConnection += "Data Source=C:\NonExistent.mdb"
    data_src.text = strConnection
    Dim objConnection as New OledbConnection(strConnection)
    try
      objConnection.Open()
      con_open.text="Connection opened successfully.<br />"
      objConnection.Close()
      con_close.text="Connection closed.<br />"
    catch e as Exception
      con_open.text="Connection failed to open.<br />"
      con_close.text=e.ToString()
    end try
  end Sub
</script>
<html>
  <body>
  <h4>Testing the data connection 
  <asp:label id="data_src" runat="server"/></h4>
  <asp:label id="con_open" runat="server"/><br />
  <asp:label id="con_close" runat="server"/><br />
  </body>
</html>



Working with Transactions with OleDbConnection (VB.net)

<%@ Page Language=VB Debug=true %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OLEDB" %>
<script runat=server>
Sub Page_Load(ByVal Sender as Object, ByVal E as EventArgs)
    Dim DBConn as OleDbConnection
    Dim DBDelete As New OleDbCommand
    Dim DBTrans As OleDbTransaction
    DBConn = New OleDbConnection( _
        "PROVIDER=Microsoft.Jet.OLEDB.4.0;" _
        & "DATA SOURCE=" _
        & Server.MapPath("EmployeeDatabase.mdb;"))
    DBConn.Open()
    DBTrans = DBConn.BeginTransaction()
    DBDelete.Connection = DBConn
    DBDelete.Transaction = DBTrans
    DBDelete.rumandText = "Delete From Employee " _
        & "Where ID = 1"
    DBDelete.ExecuteNonQuery()
    DBDelete.rumandText = "Delete From Employee " _
        & "Where ID = 2"
    DBDelete.ExecuteNonQuery()
    DBTrans.RollBack()
    lblMessage.Text = "No action was taken."
    "DBTrans.rumit()
End Sub
</SCRIPT>
<HTML>
<HEAD>
<TITLE>Working with Transactions with an Access Database</TITLE>
</HEAD>
<Body LEFTMARGIN="40">
<form runat="server">
<BR><BR>
<asp:label
    id="lblMessage"
    runat="Server"
/>
</form>
</BODY>
</HTML>


<A href="http://www.nfex.ru/Code/ASPDownload/EmployeeDatabase.zip">EmployeeDatabase.zip( 10 k)</a>

Источник — «http://nfex.ru/index.php?title=ASP.Net/ADO.net_Database/OleDbConnection&oldid=1560»