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Sql Server在.net中的数据访问辅助类

原创 Linux操作系统 作者:大可山 时间:2009-01-06 10:32:17 0 删除 编辑

// =================================================================
// SqlServer数据访问帮助类
// =================================================================

using System;
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;

namespace BrawDraw.Com.Utility
{
 ///


 /// SqlServer数据访问帮助类
 ///

    public sealed class SqlHelper
    {
        #region 私有构造函数和方法

  private SqlHelper() {}

        ///


        /// 将SqlParameter参数数组(参数值)分配给SqlCommand命令.
        /// 这个方法将给任何一个参数分配DBNull.Value;
        /// 该操作将阻止默认值的使用.
        ///

        /// 命令名
        /// SqlParameters数组
        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 )
     {
      // 检查未分配值的输出参数,将其分配以DBNull.Value.
      if ( ( p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input ) &&
       (p.Value == null))
      {
       p.Value = DBNull.Value;
      }
      command.Parameters.Add(p);
     }
    }
   }
        }

        ///


        /// 将DataRow类型的列值分配到SqlParameter参数数组.
        ///

        /// 要分配值的SqlParameter参数数组
        /// 将要分配给存储过程参数的DataRow
        private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
        {
            if ((commandParameters == null) || (dataRow == null))
            {
                return;
            }

   int i = 0;
            // 设置参数值
            foreach(SqlParameter commandParameter in commandParameters)
            {
    // 创建参数名称,如果不存在,只抛出一个异常.
    if( commandParameter.ParameterName == null ||
     commandParameter.ParameterName.Length <= 1 )
     throw new Exception(
      string.Format("请提供参数{0}一个有效的名称{1}.", i, commandParameter.ParameterName ) );
                // 从dataRow的表中获取为参数数组中数组名称的列的索引.
    // 如果存在和参数名称相同的列,则将列值赋给当前名称的参数.
    if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
                    commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
    i++;
            }
        }

        ///


        /// 将一个对象数组分配给SqlParameter参数数组.
        ///

        /// 要分配值的SqlParameter参数数组
        /// 将要分配给存储过程参数的对象数组
        private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
        {
            if ((commandParameters == null) || (parameterValues == null))
            {
                return;
            }

            // 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常.
            if (commandParameters.Length != parameterValues.Length)
            {
                throw new ArgumentException("参数值个数与参数不匹配.");
            }

            // 给参数赋值
            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[i] is IDbDataParameter)
    {
     IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
     if( paramInstance.Value == null )
     {
      commandParameters[i].Value = DBNull.Value;
     }
     else
     {
      commandParameters[i].Value = paramInstance.Value;
     }
    }
    else if (parameterValues[i] == null)
    {
     commandParameters[i].Value = DBNull.Value;
    }
    else
    {
     commandParameters[i].Value = parameterValues[i];
    }
            }
        }

        ///


        /// 预处理用户提供的命令,数据库连接/事务/命令类型/参数
        ///

        /// 要处理的SqlCommand
        /// 数据库连接
        /// 一个有效的事务或者是null值
        /// 命令类型 (存储过程,命令文本, 其它.)
        /// 存储过程名或都T-SQL命令文本
        /// 和命令相关联的SqlParameter参数数组,如果没有参数为'null'
        /// true 如果连接是打开的,则为true,其它情况下为false.
        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;
   }

            // 给命令分配一个数据库连接.
            command.Connection = connection;

            // 设置命令文本(存储过程名或SQL语句)
            command.CommandText = commandText;

            // 分配事务
            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;
            }

            // 设置命令类型.
            command.CommandType = commandType;

            // 分配命令参数
            if (commandParameters != null)
            {
                AttachParameters(command, commandParameters);
            }
            return;
        }

        #endregion 私有构造函数和方法结束

  #region RunProcedure 返回查询的参数
  ///


  /// 执行存储过程,返回影响的行数 
  ///

  /// 存储过程名
  /// 存储过程参数
  /// 影响的行数
  ///
  public static int RunProcedure(string connectionString,string storedProcName,IDataParameter[] parameters)
  {
   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    int result;
    connection.Open();
    SqlCommand command = new SqlCommand(storedProcName,connection);
    command.CommandType = CommandType.StoredProcedure;
    if(parameters!=null&¶meters.Length>0)
    {
     foreach (SqlParameter parameter in parameters)
     {
      command.Parameters.Add( parameter );
     }
    }
    command.Parameters.Add( new SqlParameter ( "ReturnValue",
     SqlDbType.Int,4,ParameterDirection.ReturnValue,
     false,0,0,string.Empty,DataRowVersion.Default,null ));
    command.ExecuteNonQuery();
    result = (int)command.Parameters["ReturnValue"].Value;
    return result;
   }
  }
 

  #endregion

        #region ExecuteNonQuery命令

        ///


        /// 执行指定连接字符串,类型的SqlCommand.
        ///

        ///
        /// 示例: 
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
        ///

        /// 一个有效的数据库连接字符串
        /// 命令类型 (存储过程,命令文本, 其它.)
        /// 存储过程名称或SQL语句
        /// 返回命令影响的行数
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        ///


        /// 执行指定连接字符串,类型的SqlCommand.如果没有提供参数,不返回结果.
        ///

        ///
        /// 示例: 
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        ///

        /// 一个有效的数据库连接字符串
        /// 命令类型 (存储过程,命令文本, 其它.)
        /// 存储过程名称或SQL语句
        /// SqlParameter参数数组
        /// 返回命令影响的行数
        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);
            }
        }

        ///


        /// 执行指定连接字符串的存储过程,将对象数组的值赋给存储过程参数,
        /// 此方法需要在参数缓存方法中探索参数并生成参数.
        ///

        ///
        /// 这个方法没有提供访问输出参数和返回值.
        /// 示例: 
        ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
        ///

        /// 一个有效的数据库连接字符串/param>
        /// 存储过程名称
        /// 分配到存储过程输入参数的对象数组
        /// 返回受影响的行数
        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" );

            // 如果存在参数值
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // 从探索存储过程参数(加载到缓存)并分配给存储过程参数数组.
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // 给存储过程参数赋值
                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
    // 没有参数情况下
                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        ///


        /// 执行指定数据库连接对象的命令
        ///

        ///
        /// 示例: 
        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
        ///

        /// 一个有效的数据库连接对象
        /// 命令类型(存储过程,命令文本或其它.)
        /// 存储过程名称或T-SQL语句
        /// 返回影响的行数
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
        }

        ///


        /// 执行指定数据库连接对象的命令
        ///

        ///
        /// 示例: 
        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        ///

        /// 一个有效的数据库连接对象
        /// 命令类型(存储过程,命令文本或其它.)
        /// T存储过程名称或T-SQL语句
        /// SqlParamter参数数组
        /// 返回影响的行数
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
   if( connection == null ) throw new ArgumentNullException( "connection" );

            // 创建SqlCommand命令,并进行预处理
            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();
     
            // 清除参数,以便再次使用.
            cmd.Parameters.Clear();
   if( mustCloseConnection )
    connection.Close();
            return retval;
        }

        ///


        /// 执行指定数据库连接对象的命令,将对象数组的值赋给存储过程参数.
        ///

        ///
        /// 此方法不提供访问存储过程输出参数和返回值
        /// 示例:  重点调用此方法
        ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
        ///

        /// 一个有效的数据库连接对象
        /// 存储过程名
        /// 分配给存储过程输入参数的对象数组
        /// 返回影响的行数
        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" );

            // 如果有参数值
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // 从缓存中加载存储过程参数
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程分配参数值
                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
            }
        }

        ///


        /// 执行带事务的SqlCommand.
        ///

        ///
        /// 示例.: 
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
        ///

        /// 一个有效的数据库连接对象
     /// 命令类型(存储过程,命令文本或其它.)
        /// 存储过程名称或T-SQL语句
        /// 返回影响的行数/returns>
        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
        }

        ///


        /// 执行带事务的SqlCommand(指定参数).
        ///

        ///
        /// 示例: 
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        ///

        /// 一个有效的数据库连接对象
        /// 命令类型(存储过程,命令文本或其它.)
        /// 存储过程名称或T-SQL语句
        /// SqlParamter参数数组
        /// 返回影响的行数
  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" );

   // 预处理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
      
   // 执行
   int retval = cmd.ExecuteNonQuery();
      
   // 清除参数集,以便再次使用.
   cmd.Parameters.Clear();
   return retval;
  }

        ///


        /// 执行带事务的SqlCommand(指定参数值).
        ///

        ///
        /// 此方法不提供访问存储过程输出参数和返回值
        /// 示例: 
        ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
        ///

        /// 一个有效的数据库连接对象
        /// 存储过程名
        /// 分配给存储过程输入参数的对象数组
        /// 返回受影响的行数
        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" );

   // 如果有参数值
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数赋值
                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
    // 没有参数值
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteNonQuery方法结束

        #region ExecuteDataset方法

        ///


        /// 执行指定数据库连接字符串的命令,返回DataSet.
        ///

        ///
        /// 示例: 
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
        ///

        /// 一个有效的数据库连接字符串
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名称或T-SQL语句
        /// 返回一个包含结果集的DataSet
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        ///


        /// 执行指定数据库连接字符串的命令,返回DataSet.
        ///

        ///
        /// 示例:
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        ///

        /// 一个有效的数据库连接字符串
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名称或T-SQL语句
        /// SqlParamters参数数组
        /// 返回一个包含结果集的DataSet
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            // 创建并打开数据库连接对象,操作完成释放对象.
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // 调用指定数据库连接字符串重载方法.
                return ExecuteDataset(connection, commandType, commandText, commandParameters);
            }
        }

  ///


  /// 执行指定数据库连接字符串的命令,直接提供参数值,返回DataSet.
  ///

  ///
  /// 此方法不提供访问存储过程输出参数和返回值.
        /// 示例:
        ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
        ///

        /// 一个有效的数据库连接字符串
        /// 存储过程名
        /// 分配给存储过程输入参数的对象数组
        /// 返回一个包含结果集的DataSet
        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))
            {
                // 从缓存中检索存储过程参数
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // 给存储过程参数分配值
                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        ///


        /// 执行指定数据库连接对象的命令,返回DataSet.
        ///

        ///
        /// 示例: 
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
        ///

        /// 一个有效的数据库连接对象
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// 返回一个包含结果集的DataSet
        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
        }
 
        ///
        /// 执行指定数据库连接对象的命令,指定存储过程参数,返回DataSet.
        ///

        ///
        /// 示例: 
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        ///

        /// 一个有效的数据库连接对象
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// SqlParamter参数数组
        /// 返回一个包含结果集的DataSet
  public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );

   // 预处理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
      
   // 创建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;
   }
  }
 
        ///


        /// 执行指定数据库连接对象的命令,指定参数值,返回DataSet.
        ///

        ///
        /// 此方法不提供访问存储过程输入参数和返回值.
        /// 示例.:  重点调用此方法
        ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
        ///

        /// 一个有效的数据库连接对象
        /// 存储过程名
        /// 分配给存储过程输入参数的对象数组
        /// 返回一个包含结果集的DataSet
        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))
            {
                // 比缓存中加载存储过程参数
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程参数分配值
                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
            }
        }

        ///


        /// 执行指定事务的命令,返回DataSet.
        ///

        ///
        /// 示例: 
        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
        ///

        /// 事务
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// 返回一个包含结果集的DataSet
        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
        }
 
        ///
        /// 执行指定事务的命令,指定参数,返回DataSet.
        ///

        ///
        /// 示例: 
        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        ///

        /// 事务
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// SqlParamter参数数组
        /// 返回一个包含结果集的DataSet
  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" );

   // 预处理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
      
   // 创建 DataAdapter & DataSet
   using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
   {
    DataSet ds = new DataSet();
    da.Fill(ds);
    cmd.Parameters.Clear();
    return ds;
   }
  }
 
        ///


        /// 执行指定事务的命令,指定参数值,返回DataSet.
        ///

        ///
        /// 此方法不提供访问存储过程输入参数和返回值.
        /// 示例.: 
        ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
        ///

        /// 事务
        /// 存储过程名
        /// 分配给存储过程输入参数的对象数组
        /// 返回一个包含结果集的DataSet
        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))
            {
                // 从缓存中加载存储过程参数
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数分配值
                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteDataset数据集命令结束
 
        #region ExecuteReader 数据阅读器

        ///


        /// 枚举,标识数据库连接是由SqlHelper提供还是由调用者提供
        ///

        private enum SqlConnectionOwnership
        {
            /// 由SqlHelper提供连接
            Internal,
            /// 由调用者提供连接
            External
        }

        ///


        /// 执行指定数据库连接对象的数据阅读器.
        ///

        ///
        /// 如果是SqlHelper打开连接,当连接关闭DataReader也将关闭.
        /// 如果是调用都打开连接,DataReader由调用都管理.
        ///

        /// 一个有效的数据库连接对象
        /// 一个有效的事务,或者为 'null'
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// SqlParameters参数数组,如果没有参数则为'null'
        /// 标识数据库连接对象是由调用者提供还是由SqlHelper提供
        /// 返回包含结果集的SqlDataReader
        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;
            // 创建命令
            SqlCommand cmd = new SqlCommand();
   try
   {
    PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
  
    // 创建数据阅读器
    SqlDataReader dataReader;

    if (connectionOwnership == SqlConnectionOwnership.External)
    {
     dataReader = cmd.ExecuteReader();
    }
    else
    {
     dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
    }
  
    // 清除参数,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;
   }
        }

        ///


        /// 执行指定数据库连接字符串的数据阅读器.
        ///

        ///
        /// 示例: 
        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
        ///

        /// 一个有效的数据库连接字符串
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// 返回包含结果集的SqlDataReader
        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        ///


        /// 执行指定数据库连接字符串的数据阅读器,指定参数.
        ///

        ///
        /// 示例: 
        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        ///

        /// 一个有效的数据库连接字符串
        /// 命令类型 (存储过程,命令文本或其它)
        /// 存储过程名或T-SQL语句
        /// SqlParamter参数数组(new SqlParameter("@prodid", 24))
        /// 返回包含结果集的SqlDataReader
        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;
            }
           
        }

        ///


        /// 执行指定数据库连接字符串的数据阅读器,指定参数值.
        ///

   &nb

来自 “ ITPUB博客 ” ,链接:http://blog.itpub.net/14601556/viewspace-528474/,如需转载,请注明出处,否则将追究法律责任。

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