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asp.net 2.0下用access开发的时候要注意的问题

發(fā)布時(shí)間：2024/4/15 asp.net 32 豆豆

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來(lái)源：http://www.study-code.com/dotnet/aspnet/67492.htm

１、數(shù)據(jù)庫(kù)要給訪問(wèn)權(quán)限，在我的電腦里，右擊access數(shù)據(jù)庫(kù)，點(diǎn)擊“屬性”菜單，選“安全”選項(xiàng)卡，選擇Users組，賦給完全控制的權(quán)限

　　如果沒(méi)有安全選項(xiàng)卡，點(diǎn)擊菜單“工具”->“文件夾選項(xiàng)”，進(jìn)入“查看”選項(xiàng)卡，把“使用簡(jiǎn)單文件共享”前的勾去掉

２、連接數(shù)據(jù)庫(kù)的時(shí)候，如果想要做到可以隨時(shí)更改數(shù)據(jù)庫(kù)的名稱(chēng)，也不用重新編譯網(wǎng)站，就把數(shù)據(jù)庫(kù)的路徑記錄在web.config文件里：

??? <connectionStrings>
????? <add name="aceConnectionString" connectionString="目錄\\數(shù)據(jù)庫(kù)名稱(chēng).mdb" providerName="System.Data.OleDb" />
??? </connectionStrings>
　　使用這兩個(gè)方法取值：

public static string connectString = "Provider=Microsoft.Jet.OleDb.4.0;Data Source=" + HttpContext.Current.Server.MapPath(ConfigurationManager.ConnectionStrings["aceConnectionString"].ConnectionString);

　　public static string GetDB()
??? {
??????? return HttpContext.Current.Server.MapPath(ConfigurationManager.ConnectionStrings["aceConnectionString"].ConnectionString);
??? }

在每個(gè)頁(yè)面，如果用到AccessDataSource控件，這個(gè)控件是不會(huì)自己讀取這個(gè)值的，可以在Page_Load頁(yè)面里，使用AdsAd.DataFile = NnllClass.GetDB();給他賦值

protected void Page_Load(object sender, EventArgs e)
??? {
??????? AdsAd.DataFile = NnllClass.GetDB();
??? }
３、如果使用AccessDataSource添加、刪除、修改記錄，要注意參數(shù)的問(wèn)題，有一些網(wǎng)站，對(duì)一些參數(shù)報(bào)錯(cuò)的信息，給出的答案說(shuō)access數(shù)據(jù)庫(kù)應(yīng)該使用拼接的sql語(yǔ)句，不可以使用參數(shù)，這種說(shuō)法是不對(duì)的，access數(shù)據(jù)庫(kù)也可以使用參數(shù)傳遞的方式增刪改查數(shù)據(jù)庫(kù)的

就是，因?yàn)関s.net 2005不可以像使用ms sql時(shí)一樣子，自動(dòng)會(huì)檢索出參數(shù)，所以全部參數(shù)要自己手動(dòng)添加，在添加參數(shù)的時(shí)候，要很小心，不要少了，也不要多了，也不要搞亂了順序

發(fā)現(xiàn)AccessDataSource控件，好像是根據(jù)綁定字段的順序來(lái)對(duì)應(yīng)傳入的參數(shù)的，也就是說(shuō)，如果你在FormView里，是這樣子綁定的：

<asp:TextBox ID="myField1TextBox" runat="server" Text='<%# Bind("myField1") %>' MaxLength="20"></asp:TextBox>
<asp:TextBox ID="myField2TextBox" runat="server" Text='<%# Bind("myField2") %>' MaxLength="20"></asp:TextBox>
定義參數(shù)的時(shí)候，就應(yīng)該這樣子定義：

?<InsertParameters>
??????????? <asp:Parameter Name="myField1" Type="String" Size="20" ConvertEmptyStringToNull="False" />
??????????? <asp:Parameter Name="myField2" Type="String" Size="20" ConvertEmptyStringToNull="False" />
??????? </InsertParameters>
次序不要搞亂了，搞亂了數(shù)據(jù)格式不同時(shí)，會(huì)報(bào)錯(cuò)，具體的出錯(cuò)信息我忘記了

定義參數(shù)的時(shí)候，還有一個(gè)要注意的問(wèn)題就是，參數(shù)名不要寫(xiě)錯(cuò)，參數(shù)不要寫(xiě)漏

使用sql數(shù)據(jù)庫(kù)時(shí)，參數(shù)名不對(duì)，或者參數(shù)個(gè)數(shù)不對(duì)，都會(huì)得到很明顯的出錯(cuò)信息，就是，access數(shù)據(jù)庫(kù)，在這種時(shí)候，是不報(bào)錯(cuò)的，如果參數(shù)名寫(xiě)錯(cuò)了，只會(huì)說(shuō)有n個(gè)參數(shù)沒(méi)有值，如果是寫(xiě)漏了參數(shù)，他有時(shí)候會(huì)直接替你更新數(shù)據(jù)庫(kù)，而更新的時(shí)候，是以綁定的順序來(lái)對(duì)應(yīng)參數(shù)的值的，這時(shí)候，如果后面的參數(shù)值，大于前面的參數(shù)對(duì)應(yīng)的字段大小，就會(huì)得到“字段太小”的出錯(cuò)信息

<InsertParameters>
??????????? <asp:Parameter Name="myField1" Type="String" Size="20" ConvertEmptyStringToNull="False" />
??????????? <asp:Parameter Name="myField2" Type="String" Size="20" ConvertEmptyStringToNull="False" />
??????? </InsertParameters>
如果少了一個(gè)

??????????? <asp:Parameter Name="myField3" Type="String" Size="200" ConvertEmptyStringToNull="False" />
在更新的時(shí)候，會(huì)把myField3的值，寫(xiě)進(jìn)myField2里，如果myField3的值的長(zhǎng)度大于20，就會(huì)報(bào)“字段太小”了

３、如果不習(xí)慣AccessDataSource控件，那就自己綁定數(shù)據(jù)吧，給出一些方法：

#region 返回?cái)?shù)據(jù)庫(kù)地址
??? public static string GetDB()
??? {
??????? return HttpContext.Current.Server.MapPath(ConfigurationManager.ConnectionStrings["aceConnectionString"].ConnectionString);
??? }
??? #endregion
???

#region 打開(kāi)數(shù)據(jù)庫(kù)：SqlConnection OpenConnect()
??? public OleDbConnection OpenConnect(Page aPage,bool setMsg)
??? {
??????? try
??????? {
??????????? OleDbConnection dbConnect = new OleDbConnection(connectString);
??????????? if (!dbConnect.State.Equals(ConnectionState.Open))
??????????? {
??????????????? dbConnect.Open();
??????????? }
??????????? return dbConnect;
??????? }
??????? catch (OleDbException ex)
??????? {
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, "連接數(shù)據(jù)庫(kù)失敗：" + ex.Message.Replace("\n", "").Replace("\r", ""));
??????????? }
??????????? return null;
??????? }
??? }
??? #endregion
???

#region 關(guān)閉數(shù)據(jù)庫(kù)：void CloseConnect(SqlConnection dbConnect)
??? public void CloseConnect(OleDbConnection dbConnect)
??? {
??????? if (dbConnect.State.Equals(ConnectionState.Open))
??????? {
??????????? dbConnect.Close();
??????? }
??? }
??? #endregion
???

#region 讀取數(shù)據(jù)，返回DataSet
??? public DataSet GetDataSet(Page aPage, OleDbConnection dbConnection, CommandType commandType, string commandText, out string msg, bool setMsg)
??? {
??????? msg = "";

??????? //創(chuàng)建并設(shè)置SqlCommand
??????? OleDbCommand dbCommand = new OleDbCommand();
??????? dbCommand.Connection = dbConnection;
??????? dbCommand.CommandType = commandType;
??????? dbCommand.CommandText = commandText;
??????? //創(chuàng)建SqlDataAdapter并獲取數(shù)據(jù)
??????? DataSet ds = new DataSet();
??????? try
??????? {
??????????? OleDbDataAdapter dataAdapter = new OleDbDataAdapter(dbCommand);
??????????? dataAdapter.Fill(ds);
??????? }
??????? catch (InvalidOperationException eo)
??????? {
??????????? msg = "讀取數(shù)據(jù)失敗：" + eo.Message.Replace("\n", "").Replace("\r", "") + "\\n";
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, msg);
??????????? }
??????? }
??????? catch (OleDbException ex)
??????? {
??????????? msg = "讀取數(shù)據(jù)失敗：" + ex.Message.Replace("\n", "").Replace("\r", "") + "\\n";
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, msg);
??????????? }
??????? }

??????? //返回?cái)?shù)據(jù)
??????? return ds;
??? }
??? #endregion

???

#region 讀取數(shù)據(jù)，返回SqlDataReader
??? public OleDbDataReader GetDataReader(Page aPage, OleDbConnection dbConnection, CommandType commandType, string commandText, OleDbParameter[] p, out string msg, bool setMsg)
??? {
??????? msg = "";
??????? //設(shè)置命令
??????? OleDbCommand dbCommand = new OleDbCommand();
??????? dbCommand.Connection = dbConnection;
??????? dbCommand.CommandType = commandType;
??????? dbCommand.CommandText = commandText;
??????? //設(shè)置參數(shù)
??????? if (p != null)
??????? {
??????????? foreach (OleDbParameter pi in p)
??????????? {
??????????????? dbCommand.Parameters.Add(pi);
??????????? }
??????? }
??????? //讀取第一個(gè)結(jié)果集
??????? OleDbDataReader dbReader = null;
??????? try
??????? {
??????????? dbReader = dbCommand.ExecuteReader();
??????? }
??????? catch (InvalidOperationException eo)
??????? {
??????????? msg = "讀取數(shù)據(jù)失敗：" + eo.Message.Replace("\n", "").Replace("\r", "") + "\\n";
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, msg);
??????????? }
??????? }
??????? catch (OleDbException ex)
??????? {
??????????? msg = "讀取數(shù)據(jù)失敗：" + ex.Message.Replace("\n", "").Replace("\r", "") + "\\n";
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, msg);
??????????? }
??????? }
??????? return dbReader;
??? }
??? #endregion
???

#region 執(zhí)行sql命令或存儲(chǔ)過(guò)程
??? public int execCommand(Page aPage, OleDbConnection dbConnection, CommandType commandType, string commandText, OleDbParameter[] p, out string msg, bool setMsg)
??? {
??????? bool needCloseDB = false;
??????? int row = 0;
??????? msg = "";
??????? //創(chuàng)建并設(shè)置SqlConnection
??????? if (dbConnection == null)
??????? {
??????????? needCloseDB = true;
??????????? dbConnection = OpenConnect(aPage, setMsg);
??????????? if (dbConnection == null) return -1;
??????? }
??????? //創(chuàng)建并設(shè)置SqlCommand
??????? OleDbCommand dbCommand = new OleDbCommand();
??????? dbCommand.Connection = dbConnection;
??????? dbCommand.CommandType = commandType;
??????? dbCommand.CommandText = commandText;
??????? //設(shè)置參數(shù)
??????? if (p != null)
??????? {
??????????? foreach (OleDbParameter pi in p)
??????????? {
??????????????? dbCommand.Parameters.Add(pi);
??????????? }
??????? }
??????? //執(zhí)行命令
??????? try
??????? {
??????????? row = dbCommand.ExecuteNonQuery();
??????? }
??????? catch (InvalidOperationException eo)
??????? {
??????????? msg = eo.Message.Replace("\n", "").Replace("\r", "") + "\\n";
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, msg);
??????????? }
??????????? row = -1;
??????? }
??????? catch (OleDbException ex)
??????? {
??????????? //執(zhí)行過(guò)程出錯(cuò)
??????????? msg = ex.Message.Replace("\n", "").Replace("\r", "") + "\\n";
??????????? if (setMsg)
??????????? {
??????????????? SetMsgJS(aPage.Master, msg);
??????????? }
??????????? row = -1;
??????? }
??????? //關(guān)閉數(shù)據(jù)庫(kù)
??????? if (needCloseDB)
??????? {
??????????? CloseConnect(dbConnection);
??????? }
??????? return row;
??? }
??? #endregion
上面的方法都用到一個(gè)SetMsgJS方法，這個(gè)方法是用來(lái)給母版頁(yè)設(shè)置信息的

public static void SetMsgJS(MasterPage masterPage, string msg)
??? {
??????? Literal lt = (Literal)masterPage.FindControl("LiteralMsg");
??????? if (lt != null)
??????? {
??????????? lt.Text += msg;
??????? }
??? }
在母版頁(yè)里定義是這樣子的：
???

轉(zhuǎn)載于:https://www.cnblogs.com/kangshifu/archive/2008/08/11/1265124.html

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