微軟官方的SQLHelper類(含完整中文註釋)（轉）
阿新 • • 發佈：2018-12-09
資料庫操作類真的沒有必要自己去寫，因為成熟的類庫真的非常完善了，拿來直接用就好，省時省力。
裡面的函式一堆，常用的就那幾個，無非就是增刪改查嘛，來看下幾種常用的函式：
1.ExecuteNonQuery 執行增刪改
2.ExecuteReader 執行查詢
3.ExecuteScalar 返回首行首列
使用方法介紹
Web.config配置
1 <connectionStrings> 2 <add name="ConnectionString" connectionString="server=127.0.0.1;uid=sa;pwd=ok;database=PetShop;Max Pool Size =512; Min Pool Size=0; Connection Lifetime = 300;packet size=1000;" providerName="System.Data.SqlClient" /> 3 </connectionStrings>
呼叫函式的寫法
1 sql = "UPDATE Student set Name = @Name WHERE Id = @Id"; 2 SqlHelper.ExecuteNonQuery(CommandType.Text, sql, new SqlParameter[]{ 3 new SqlParameter("@Name", name), 4 new SqlParameter("@Id", id) 5 });
這樣呼叫就比較簡化，而且比較靈活
using System; using System.Data; using System.Xml; using System.Data.SqlClient; using System.Collections; namespace myhelper { /// <summary> /// SqlServer資料訪問幫助類 /// </summary> public sealed class SqlHelper { #region 私有建構函式和方法 private SqlHelper() {}/// <summary> /// 將SqlParameter引數陣列(引數值)分配給SqlCommand命令. /// 這個方法將給任何一個引數分配DBNull.Value; /// 該操作將阻止預設值的使用. /// </summary>SqlHelperSqlHelper /// <param>命令名</param> /// <param>SqlParameters陣列</param> private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters) { if( command == null ) throw new ArgumentNullException( "command" ); if( commandParameters != null ) { foreach (SqlParameter p in commandParameters) { if( p != null ) { // 檢查未分配值的輸出引數,將其分配以DBNull.Value. if ( ( p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input ) && (p.Value == null)) { p.Value = DBNull.Value; } command.Parameters.Add(p); } } } } /// <summary> /// 將DataRow型別的列值分配到SqlParameter引數陣列. /// </summary> /// <param>要分配值的SqlParameter引數陣列</param> /// <param>將要分配給儲存過程引數的DataRow</param> private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow) { if ((commandParameters == null) || (dataRow == null)) { return; } int i = 0; // 設定引數值 foreach(SqlParameter commandParameter in commandParameters) { // 建立引數名稱,如果不存在,只丟擲一個異常. if( commandParameter.ParameterName == null || commandParameter.ParameterName.Length <= 1 ) throw new Exception( string.Format("請提供引數{0}一個有效的名稱{1}.", i, commandParameter.ParameterName ) ); // 從dataRow的表中獲取為引數陣列中陣列名稱的列的索引. // 如果存在和引數名稱相同的列,則將列值賦給當前名稱的引數. if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1) commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)]; i++; } } /// <summary> /// 將一個物件陣列分配給SqlParameter引數陣列. /// </summary> /// <param>要分配值的SqlParameter引數陣列</param> /// <param>將要分配給儲存過程引數的物件陣列</param> private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues) { if ((commandParameters == null) || (parameterValues == null)) { return; } // 確保物件陣列個數與引數個數匹配,如果不匹配,丟擲一個異常. if (commandParameters.Length != parameterValues.Length) { throw new ArgumentException("引數值個數與引數不匹配."); } // 給引數賦值 for (int i = 0, j = commandParameters.Length; i < j; i++) { // If the current array value derives from IDbDataParameter, then assign its Value property if (parameterValues is IDbDataParameter) { IDbDataParameter paramInstance = (IDbDataParameter)parameterValues; if( paramInstance.Value == null ) { commandParameters.Value = DBNull.Value; } else { commandParameters.Value = paramInstance.Value; } } else if (parameterValues == null) { commandParameters.Value = DBNull.Value; } else { commandParameters.Value = parameterValues; } } } /// <summary> /// 預處理使用者提供的命令,資料庫連線/事務/命令型別/引數 /// </summary> /// <param>要處理的SqlCommand</param> /// <param>資料庫連線</param> /// <param>一個有效的事務或者是null值</param> /// <param>命令型別 (儲存過程,命令文字, 其它.)</param> /// <param>儲存過程名或都T-SQL命令文字</param> /// <param>和命令相關聯的SqlParameter引數陣列,如果沒有引數為'null'</param> /// <param><c>true</c> 如果連線是開啟的,則為true,其它情況下為false.</param> private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, out bool mustCloseConnection ) { if( command == null ) throw new ArgumentNullException( "command" ); if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" ); // If the provided connection is not open, we will open it if (connection.State != ConnectionState.Open) { mustCloseConnection = true; connection.Open(); } else { mustCloseConnection = false; } // 給命令分配一個數據庫連線. command.Connection = connection; // 設定命令文字(儲存過程名或SQL語句) command.CommandText = commandText; // 分配事務 if (transaction != null) { if( transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" ); command.Transaction = transaction; } // 設定命令型別. command.CommandType = commandType; // 分配命令引數 if (commandParameters != null) { AttachParameters(command, commandParameters); } return; } #endregion 私有建構函式和方法結束 #region ExecuteNonQuery命令 /// <summary> /// 執行指定連線字串,型別的SqlCommand. /// </summary> /// <remarks> /// 示例: /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders"); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>命令型別 (儲存過程,命令文字, 其它.)</param> /// <param>儲存過程名稱或SQL語句</param> /// <returns>返回命令影響的行數</returns> public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText) { return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行指定連線字串,型別的SqlCommand.如果沒有提供引數,不返回結果. /// </summary> /// <remarks> /// 示例: /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>命令型別 (儲存過程,命令文字, 其它.)</param> /// <param>儲存過程名稱或SQL語句</param> /// <param>SqlParameter引數陣列</param> /// <returns>返回命令影響的行數</returns> public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" ); using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); return ExecuteNonQuery(connection, commandType, commandText, commandParameters); } } /// <summary> /// 執行指定連線字串的儲存過程,將物件陣列的值賦給儲存過程引數, /// 此方法需要在引數快取方法中探索引數並生成引數. /// </summary> /// <remarks> /// 這個方法沒有提供訪問輸出引數和返回值. /// 示例: /// int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36); /// </remarks> /// <param>一個有效的資料庫連線字串/param> /// <param>儲存過程名稱</param> /// <param>分配到儲存過程輸入引數的物件陣列</param> /// <returns>返回受影響的行數</returns> public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues) { if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); // 如果存在引數值 if ((parameterValues != null) && (parameterValues.Length > 0)) { // 從探索儲存過程引數(載入到快取)並分配給儲存過程引數陣列. SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName); // 給儲存過程引數賦值 AssignParameterValues(commandParameters, parameterValues); return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters); } else { // 沒有引數情況下 return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName); } } /// <summary> /// 執行指定資料庫連線物件的命令 /// </summary> /// <remarks> /// 示例: /// int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders"); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別(儲存過程,命令文字或其它.)</param> /// <param>儲存過程名稱或T-SQL語句</param> /// <returns>返回影響的行數</returns> public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText) { return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行指定資料庫連線物件的命令 /// </summary> /// <remarks> /// 示例: /// int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別(儲存過程,命令文字或其它.)</param> /// <param>T儲存過程名稱或T-SQL語句</param> /// <param>SqlParamter引數陣列</param> /// <returns>返回影響的行數</returns> public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( connection == null ) throw new ArgumentNullException( "connection" ); // 建立SqlCommand命令,並進行預處理 SqlCommand cmd = new SqlCommand(); bool mustCloseConnection = false; PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection ); // Finally, execute the command int retval = cmd.ExecuteNonQuery(); // 清除引數,以便再次使用. cmd.Parameters.Clear(); if( mustCloseConnection ) connection.Close(); return retval; } /// <summary> /// 執行指定資料庫連線物件的命令,將物件陣列的值賦給儲存過程引數. /// </summary> /// <remarks> /// 此方法不提供訪問儲存過程輸出引數和返回值 /// 示例: /// int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>儲存過程名</param> /// <param>分配給儲存過程輸入引數的物件陣列</param> /// <returns>返回影響的行數</returns> public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues) { if( connection == null ) throw new ArgumentNullException( "connection" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); // 如果有引數值 if ((parameterValues != null) && (parameterValues.Length > 0)) { // 從快取中載入儲存過程引數 SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName); // 給儲存過程分配引數值 AssignParameterValues(commandParameters, parameterValues); return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters); } else { return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName); } } /// <summary> /// 執行帶事務的SqlCommand. /// </summary> /// <remarks> /// 示例.: /// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders"); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別(儲存過程,命令文字或其它.)</param> /// <param>儲存過程名稱或T-SQL語句</param> /// <returns>返回影響的行數/returns> public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText) { return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行帶事務的SqlCommand(指定引數). /// </summary> /// <remarks> /// 示例: /// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別(儲存過程,命令文字或其它.)</param> /// <param>儲存過程名稱或T-SQL語句</param> /// <param>SqlParamter引數陣列</param> /// <returns>返回影響的行數</returns> public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( transaction == null ) throw new ArgumentNullException( "transaction" ); if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" ); // 預處理 SqlCommand cmd = new SqlCommand(); bool mustCloseConnection = false; PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection ); // 執行 int retval = cmd.ExecuteNonQuery(); // 清除引數集,以便再次使用. cmd.Parameters.Clear(); return retval; } /// <summary> /// 執行帶事務的SqlCommand(指定引數值). /// </summary> /// <remarks> /// 此方法不提供訪問儲存過程輸出引數和返回值 /// 示例: /// int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>儲存過程名</param> /// <param>分配給儲存過程輸入引數的物件陣列</param> /// <returns>返回受影響的行數</returns> public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues) { if( transaction == null ) throw new ArgumentNullException( "transaction" ); if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); // 如果有引數值 if ((parameterValues != null) && (parameterValues.Length > 0)) { // 從快取中載入儲存過程引數,如果快取中不存在則從資料庫中檢索引數資訊並載入到快取中. () SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName); // 給儲存過程引數賦值 AssignParameterValues(commandParameters, parameterValues); // 呼叫過載方法 return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters); } else { // 沒有引數值 return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName); } } #endregion ExecuteNonQuery方法結束 #region ExecuteDataset方法 /// <summary> /// 執行指定資料庫連線字串的命令,返回DataSet. /// </summary> /// <remarks> /// 示例: /// DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders"); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名稱或T-SQL語句</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText) { return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行指定資料庫連線字串的命令,返回DataSet. /// </summary> /// <remarks> /// 示例: /// DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名稱或T-SQL語句</param> /// <param>SqlParamters引數陣列</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" ); // 建立並開啟資料庫連線物件,操作完成釋放物件. using (SqlConnection connection = new SqlConnection(connectionString)) { connection.Open(); // 呼叫指定資料庫連線字串過載方法. return ExecuteDataset(connection, commandType, commandText, commandParameters); } } /// <summary> /// 執行指定資料庫連線字串的命令,直接提供引數值,返回DataSet. /// </summary> /// <remarks> /// 此方法不提供訪問儲存過程輸出引數和返回值. /// 示例: /// DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>儲存過程名</param> /// <param>分配給儲存過程輸入引數的物件陣列</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues) { if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); if ((parameterValues != null) && (parameterValues.Length > 0)) { // 從快取中檢索儲存過程引數 SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName); // 給儲存過程引數分配值 AssignParameterValues(commandParameters, parameterValues); return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters); } else { return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName); } } /// <summary> /// 執行指定資料庫連線物件的命令,返回DataSet. /// </summary> /// <remarks> /// 示例: /// DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders"); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText) { return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行指定資料庫連線物件的命令,指定儲存過程引數,返回DataSet. /// </summary> /// <remarks> /// 示例: /// DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <param>SqlParamter引數陣列</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( connection == null ) throw new ArgumentNullException( "connection" ); // 預處理 SqlCommand cmd = new SqlCommand(); bool mustCloseConnection = false; PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection ); // 建立SqlDataAdapter和DataSet. using( SqlDataAdapter da = new SqlDataAdapter(cmd) ) { DataSet ds = new DataSet(); // 填充DataSet. da.Fill(ds); cmd.Parameters.Clear(); if( mustCloseConnection ) connection.Close(); return ds; } } /// <summary> /// 執行指定資料庫連線物件的命令,指定引數值,返回DataSet. /// </summary> /// <remarks> /// 此方法不提供訪問儲存過程輸入引數和返回值. /// 示例.: /// DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>儲存過程名</param> /// <param>分配給儲存過程輸入引數的物件陣列</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues) { if( connection == null ) throw new ArgumentNullException( "connection" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); if ((parameterValues != null) && (parameterValues.Length > 0)) { // 比快取中載入儲存過程引數 SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName); // 給儲存過程引數分配值 AssignParameterValues(commandParameters, parameterValues); return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters); } else { return ExecuteDataset(connection, CommandType.StoredProcedure, spName); } } /// <summary> /// 執行指定事務的命令,返回DataSet. /// </summary> /// <remarks> /// 示例: /// DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders"); /// </remarks> /// <param>事務</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText) { return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行指定事務的命令,指定引數,返回DataSet. /// </summary> /// <remarks> /// 示例: /// DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>事務</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <param>SqlParamter引數陣列</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( transaction == null ) throw new ArgumentNullException( "transaction" ); if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" ); // 預處理 SqlCommand cmd = new SqlCommand(); bool mustCloseConnection = false; PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection ); // 建立 DataAdapter & DataSet using( SqlDataAdapter da = new SqlDataAdapter(cmd) ) { DataSet ds = new DataSet(); da.Fill(ds); cmd.Parameters.Clear(); return ds; } } /// <summary> /// 執行指定事務的命令,指定引數值,返回DataSet. /// </summary> /// <remarks> /// 此方法不提供訪問儲存過程輸入引數和返回值. /// 示例.: /// DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36); /// </remarks> /// <param>事務</param> /// <param>儲存過程名</param> /// <param>分配給儲存過程輸入引數的物件陣列</param> /// <returns>返回一個包含結果集的DataSet</returns> public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues) { if( transaction == null ) throw new ArgumentNullException( "transaction" ); if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); if ((parameterValues != null) && (parameterValues.Length > 0)) { // 從快取中載入儲存過程引數 SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName); // 給儲存過程引數分配值 AssignParameterValues(commandParameters, parameterValues); return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters); } else { return ExecuteDataset(transaction, CommandType.StoredProcedure, spName); } } #endregion ExecuteDataset資料集命令結束 #region ExecuteReader 資料閱讀器 /// <summary> /// 列舉,標識資料庫連線是由SqlHelper提供還是由呼叫者提供 /// </summary> private enum SqlConnectionOwnership { /// <summary>由SqlHelper提供連線</summary> Internal, /// <summary>由呼叫者提供連線</summary> External } /// <summary> /// 執行指定資料庫連線物件的資料閱讀器. /// </summary> /// <remarks> /// 如果是SqlHelper開啟連線,當連線關閉DataReader也將關閉. /// 如果是呼叫都開啟連線,DataReader由呼叫都管理. /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>一個有效的事務,或者為 'null'</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <param>SqlParameters引數陣列,如果沒有引數則為'null'</param> /// <param>標識資料庫連線物件是由呼叫者提供還是由SqlHelper提供</param> /// <returns>返回包含結果集的SqlDataReader</returns> private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership) { if( connection == null ) throw new ArgumentNullException( "connection" ); bool mustCloseConnection = false; // 建立命令 SqlCommand cmd = new SqlCommand(); try { PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection ); // 建立資料閱讀器 SqlDataReader dataReader; if (connectionOwnership == SqlConnectionOwnership.External) { dataReader = cmd.ExecuteReader(); } else { dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection); } // 清除引數,以便再次使用.. // HACK: There is a problem here, the output parameter values are fletched // when the reader is closed, so if the parameters are detached from the command // then the SqlReader can磘 set its values. // When this happen, the parameters can磘 be used again in other command. bool canClear = true; foreach(SqlParameter commandParameter in cmd.Parameters) { if (commandParameter.Direction != ParameterDirection.Input) canClear = false; } if (canClear) { cmd.Parameters.Clear(); } return dataReader; } catch { if( mustCloseConnection ) connection.Close(); throw; } } /// <summary> /// 執行指定資料庫連線字串的資料閱讀器. /// </summary> /// <remarks> /// 示例: /// SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders"); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <returns>返回包含結果集的SqlDataReader</returns> public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText) { return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null); } /// <summary> /// 執行指定資料庫連線字串的資料閱讀器,指定引數. /// </summary> /// <remarks> /// 示例: /// SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <param>SqlParamter引數陣列(new SqlParameter("@prodid", 24))</param> /// <returns>返回包含結果集的SqlDataReader</returns> public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters) { if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" ); SqlConnection connection = null; try { connection = new SqlConnection(connectionString); connection.Open(); return ExecuteReader(connection, null, commandType, commandText, commandParameters,SqlConnectionOwnership.Internal); } catch { // If we fail to return the SqlDatReader, we need to close the connection ourselves if( connection != null ) connection.Close(); throw; } } /// <summary> /// 執行指定資料庫連線字串的資料閱讀器,指定引數值. /// </summary> /// <remarks> /// 此方法不提供訪問儲存過程輸出引數和返回值引數. /// 示例: /// SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36); /// </remarks> /// <param>一個有效的資料庫連線字串</param> /// <param>儲存過程名</param> /// <param>分配給儲存過程輸入引數的物件陣列</param> /// <returns>返回包含結果集的SqlDataReader</returns> public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues) { if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" ); if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" ); if ((parameterValues != null) && (parameterValues.Length > 0)) { SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName); AssignParameterValues(commandParameters, parameterValues); return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters); } else { return ExecuteReader(connectionString, CommandType.StoredProcedure, spName); } } /// <summary> /// 執行指定資料庫連線物件的資料閱讀器. /// </summary> /// <remarks> /// 示例: /// SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders"); /// </remarks> /// <param>一個有效的資料庫連線物件</param> /// <param>命令型別 (儲存過程,命令文字或其它)</param> /// <param>儲存過程名或T-SQL語句</param> /// <returns>返回包含結果集的SqlDataReader</returns> public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText) { return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null); } /// <summary> /// [呼叫者方式]執行指定資料庫連線物件的資料閱讀器,指定引數. /// </summary> ///