1 連接SQL Server數據庫示例 // 連接字符串string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"]; // 創建SqlConnection對象SqlConnection connection = new SqlConnection(ConnectionString); try{// 打開數據庫連接connection.Open(); myLabel.Text = "連接數據庫成功";}catch{myLabel.Text = "連接數據庫失敗";}finally{// 關閉數據庫連接connection.Close(); }<appSettings><add key="ConnectionSqlServer" value="Server=(local);User id=sa;Pwd=sa;Database=Northwind"></add><add key="ConnectionSqlServer1" value="Server=(local);User id=sa;Pwd=sa;"></add><add key="ConnectionSqlServer_tempdb" value="Server=(local);User id=sa;Pwd=sa;Database=tempdb"></add><add key="ConnectionDB2" value="DATABASE=SAMPLE;UID=username;PWD=password"></add><add key="ConnectionOracle" value="Data Source=Oracle8i;Integrated Security=yes"></add></appSettings> <system.web>2 // 連接到 ACCESS 的連接字符串string ConnStr = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=" + Server.MapPath("grocertogo.mdb");// 使用OleDb .NET數據提供程序創建連接OleDbConnection oleConnection = new OleDbConnection(ConnStr);try{// 打開數據庫連接oleConnection.Open();// 顯示連接成功信息myLabel.Text = "Access數據庫連接狀態：" + oleConnection.State;}catch(Exception ex){// 如果出現異常，顯示異常信息myLabel.Text = "Access數據庫連接狀態：" + ex.ToString();}finally{// 關閉數據庫連接oleConnection.Close(); }3 // 連接到 Oracle 數據庫示例string ORACLE_ConnStr = "Data Source=Oracle8i;Integrated Security=yes";// 創建 OracleConnection 對象OracleConnection oConnection = new OracleConnection(ORACLE_ConnStr);try{oConnection.Open();myLabel.Text = "連接到 Oracle 數據庫";}catch(Exception ex){myLabel.Text = ex.ToString();}finally{oConnection.Close();} 4 SqlCommand 執行SQL命令示例string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];// 創建SqlConnection對象// 創建Command對象SqlConnection thisConnection = new SqlConnection(ConnStr);SqlCommand thisCommand = new SqlCommand();// 關聯Connection對象// 賦值SQL語句到CommandText屬性// 指定命令類型是Sql語句thisCommand.Connection = thisConnection;thisCommand.CommandText = "SELECT COUNT(*) FROM Employees";thisCommand.CommandType = CommandType.Text;try{// 打開數據庫連接thisCommand.Connection.Open();// 獲取查詢結果myLabel.Text = thisCommand.ExecuteScalar().ToString();}catch(SqlException ex){// 如果出現異常，在Label標簽中顯示異常信息myLabel.Text = ex.ToString();}finally{// 關閉數據庫連接thisCommand.Connection.Close();}5 SqlDataReader 讀取數據示例string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];string Sql = "SELECT LastName, FirstName FROM Employees";SqlConnection thisConnection = new SqlConnection(ConnectionString);SqlCommand thisCommand = new SqlCommand(Sql, thisConnection);thisCommand.CommandType = CommandType.Text;try{// 打開數據庫連接thisCommand.Connection.Open();// 執行SQL語句，并返回DataReader對象SqlDataReader dr = thisCommand.ExecuteReader();// 以粗體顯示標題myLabel.Text = "<b>LastName FirstName</b><br>";// 循環讀取結果集while(dr.Read()){// 讀取兩個列值并輸出到Label中myLabel.Text += dr["LastName"] + " " + dr["FirstName"] + "<br>";}// 關閉DataReaderdr.Close();}catch(SqlException ex){// 異常處理Response.Write(ex.ToString());}finally{// 關閉數據庫連接thisCommand.Connection.Close();}6 使用DataAdapter填充數據到DataSetstring ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];string Sql = "SELECT EmployeeID, LastName, FirstName,Title, TitleOfCourtesy, BirthDate FROM Employees";// 創建SqlConnection對象// 創建DataAdapter對象并初始化SqlConnection thisConnection = new SqlConnection(ConnectionString);SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection);// 創建DataSet對象DataSet data = new DataSet();// 填充數據到DataSetadapter.Fill(data);// 數據綁定myDataGrid.DataSource = data;myDataGrid.DataBind();7 使用DataTable存儲數據庫表內容string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];string Sql = "SELECT EmployeeID, LastName, FirstName, BirthDate FROM Employees";// 創建SqlConnection、SqlDataAdapter對象SqlConnection thisConnection = new SqlConnection(ConnectionString);SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection); // 創建DataTable對象DataTable table = new DataTable();// 填充數據到DataTableadapter.Fill(table);// 將DataTable綁定到DataGrid控件myDataGrid.DataSource = table;myDataGrid.DataBind();8 將數據庫數據填充到 XML 文件 // 連接字符串及 SQL 語句string ConnString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];string Sql = "SELECT CustomerID,CompanyName,Country FROM Customers";// 連接 SqlConnection 及 SqlDataAdapter 對象SqlConnection thisConnection = new SqlConnection(ConnString);SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection);// 創建 DataSet 對象DataSet data = new DataSet();// 填充 DataSetadapter.Fill(data, "Customers");// 將 DataSet 數據其及架構填充到 Xml 文件data.WriteXml(Server.MapPath(".") + "\\myXml.xml", XmlWriteMode.WriteSchema);// 提示填充是否成功Label1.Text = "填充到XML文件成功";9 ASP.NET 使用存儲過程// 連接字符串string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];// 創建Connection對象SqlConnection myConn = new SqlConnection(ConnStr);// 創建Command對象并和Connection對象關聯SqlCommand myCommand = new SqlCommand();myCommand.Connection = myConn;// 指定要執行的存儲過程名稱myCommand.CommandText = "CustomersProc";// 使用要執行的是存儲過程myCommand.CommandType = CommandType.StoredProcedure;// 創建DataAdapter對象填充數據DataSet myDS = new DataSet();SqlDataAdapter adapter = new SqlDataAdapter(myCommand);adapter.Fill(myDS, "Customers");// 將返回的數據和DataGrid綁定顯示myDataGrid.DataSource = myDS.Tables["Customers"];myDataGrid.DataBind();10 使用帶輸入參數的存儲過程 string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];// 創建數據庫操作對象SqlDataAdapter myAdapter = new SqlDataAdapter();SqlCommand myCommand = new SqlCommand();myCommand.Connection = new SqlConnection(ConnStr);DataTable dt = new DataTable();// 指定要調用的存儲過程名稱 "Customer_Select"// 指定SqlCommand對象的命令類型為 "StoredProcedure"枚舉值myCommand.CommandText = "Customer_Select";myCommand.CommandType = CommandType.StoredProcedure;// 創建SqlParameter對象，指定參數名稱、數據類型、長度及參數值SqlParameter para = new SqlParameter("@country", SqlDbType.NVarChar, 15);para.Value = DropDownList1.SelectedValue;myCommand.Parameters.Add(para);// 關聯SqlDataAdapter與SqlCommand對象myAdapter.SelectCommand = myCommand;myAdapter.Fill(dt);// 綁定DataGridDataGrid1.DataSource = dt;DataGrid1.DataBind();11 使用帶輸入、輸出參數的存儲過程示 string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];// 創建 Connection 和 Command 對象SqlConnection myConn = new SqlConnection(ConnStr);SqlCommand myCommand = new SqlCommand("EmployeesProc", myConn);// 指定要執行的命令為存儲過程myCommand.CommandType = CommandType.StoredProcedure;// 增加輸入參數并賦值myCommand.Parameters.Add("@TitleOfCourtesy", SqlDbType.NVarChar, 20);myCommand.Parameters["@TitleOfCourtesy"].Value = myDropDownList.SelectedItem.Text;myCommand.Parameters["@TitleOfCourtesy"].Direction = ParameterDirection.Input;// 增加輸出參數myCommand.Parameters.Add("@empCount", SqlDbType.Int);myCommand.Parameters["@empCount"].Direction = ParameterDirection.Output;// 創建 DataAdapter 對象填充數據DataSet myDS = new DataSet();SqlDataAdapter adapter = new SqlDataAdapter(myCommand);adapter.Fill(myDS, "Customers");// 使用 Label 控件顯示輸出參數的輸出值rtnLabel.Text = myCommand.Parameters["@empCount"].Value.ToString();// 將返回的數據和 DataGrid 綁定顯示myDataGrid.DataSource = myDS.Tables["Customers"];myDataGrid.DataBind();12 獲得數據庫中表的數目和名稱 獲取服務器端數據庫列表 string listQuery = "SELECT name FROM sysobjects WHERE xtype = 'U'"; string sumQuery = "SELECT COUNT(*) FROM sysobjects WHERE xtype = 'U'string db_query = "sp_helpdb";13 保存圖片到SQL Server數據庫示例// HttpPostedFile對象，用于讀取圖象文件屬性HttpPostedFile UpFile = UP_FILE.PostedFile;// FileLength 變量存儲圖片的字節大小int FileLength = UpFile.ContentLength;try{if (FileLength == 0){txtMessage.Text = "<b>您未選擇上傳的文件</b>";}else{// 創建存儲圖片文件的臨時 Byte 數組Byte[] FileByteArray = new Byte[FileLength];// 建立數據流對象Stream StreamObject = UpFile.InputStream; // 讀取圖象文件數據，FileByteArray為數據儲存體，0為數據指針位置、FileLnegth為數據長度StreamObject.Read(FileByteArray,0,FileLength); // 數據庫操作string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];string query = "INSERT INTO ImageTable (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@ImageData, @ImageContentType, @ImageDescription, @ImageSize)";SqlCommand myCommand = new SqlCommand(query, new SqlConnection(ConnStr));// 添加各項參數并賦值myCommand.Parameters.Add("@ImageData", SqlDbType.Image);myCommand.Parameters.Add("@ImageContentType", SqlDbType.VarChar, 50);myCommand.Parameters.Add("@ImageDescription", SqlDbType.VarChar, 200);myCommand.Parameters.Add("@ImageSize", SqlDbType.BigInt);myCommand.Parameters["@ImageData"].Value = FileByteArray;myCommand.Parameters["@ImageContentType"].Value = UpFile.ContentType;myCommand.Parameters["@ImageDescription"].Value = txtDescription.Text;myCommand.Parameters["@ImageSize"].Value = FileLength;// 執行數據庫操作myCommand.Connection.Open();myCommand.ExecuteNonQuery();myCommand.Connection.Close();// 提示上傳成功txtMessage.Text = "<b>上傳文件成功</b>";}} catch (Exception ex) {// 使用 Label 標簽顯示異常txtMessage.Text = ex.Message.ToString();}14 獲得插入記錄標識號的示例 // 數據庫連接字符串string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];// 創建插入SQL語句及調用@@identity函數返回標識值string insert_query = "insert into Categories (CategoryName,Description) values ('IT', 'Internet');"+ "SELECT @@identity AS 'identity';";// 執行數據庫操作SqlCommand myCommand = new SqlCommand(insert_query, new SqlConnection(ConnStr));myCommand.Connection.Open();myLabel.Text = myCommand.ExecuteScalar().ToString();myCommand.Connection.Close(); 15 如何讀取Excel表格中的數據// 獲取Excep文件的完整路徑string source = File1.Value;string ConnStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + source + ";Extended Properties=Excel 8.0";string query = "SELECT * FROM [Sheet1$]";OleDbCommand oleCommand = new OleDbCommand(query, new OleDbConnection(ConnStr));OleDbDataAdapter oleAdapter = new OleDbDataAdapter(oleCommand);DataSet myDataSet = new DataSet();// 將 Excel 的[Sheet1]表內容填充到 DataSet 對象oleAdapter.Fill(myDataSet, "[Sheet1$]");// 數據綁定DataGrid1.DataSource = myDataSet;DataGrid1.DataMember = "[Sheet1$]";DataGrid1.DataBind();

轉載于:https://www.cnblogs.com/hulang/archive/2010/12/27/1917825.html

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