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  • 企业库 OracleHelper

    using System;
    using System.Data;
    using System.Data.OracleClient;
    using System.Collections;

    namespace Anboo.Steel.Utility
    {
        /// <summary>
        /// The OracleHelper class is intended to encapsulate high performance, scalable best practices for
        /// common uses of OracleClient.
        /// </summary>
        public sealed class OracleHelper
        {
            #region private utility methods & constructors

            //Since this class provides only static methods, make the default constructor private to prevent
            //instances from being created with "new OracleHelper()".
            private OracleHelper() { }

            /// <summary>
            /// This method is used to attach array's of OracleParameters to an OracleCommand.
            ///
            /// This method will assign a value of DbNull to any parameter with a direction of
            /// InputOutput and a value of null. 
            ///
            /// This behavior will prevent default values from being used, but
            /// this will be the less common case than an intended pure output parameter (derived as InputOutput)
            /// where the user provided no input value.
            /// </summary>
            /// <param name="command">The command to which the parameters will be added</param>
            /// <param name="commandParameters">an array of OracleParameters tho be added to command</param>
            private static void AttachParameters(OracleCommand command, OracleParameter[] commandParameters)
            {
                foreach (OracleParameter p in commandParameters)
                {
                    //check for derived output value with no value assigned
                    if ((p.Direction == ParameterDirection.InputOutput) && (p.Value == null))
                    {
                        p.Value = DBNull.Value;
                    }

                    command.Parameters.Add(p);
                }
            }

            /// <summary>
            /// This method assigns an array of values to an array of OracleParameters.
            /// </summary>
            /// <param name="commandParameters">array of OracleParameters to be assigned values</param>
            /// <param name="parameterValues">array of objects holding the values to be assigned</param>
            private static void AssignParameterValues(OracleParameter[] commandParameters, object[] parameterValues)
            {
                if ((commandParameters == null) || (parameterValues == null))
                {
                    //do nothing if we get no data
                    return;
                }

                // we must have the same number of values as we pave parameters to put them in
                if (commandParameters.Length != parameterValues.Length)
                {
                    throw new ArgumentException("Parameter count does not match Parameter Value count.");
                }

                //iterate through the OracleParameters, assigning the values from the corresponding position in the
                //value array
                for (int i = 0, j = commandParameters.Length; i < j; i++)
                {
                    commandParameters[i].Value = parameterValues[i];
                }
            }

            /// <summary>
            /// This method opens (if necessary) and assigns a connection, transaction, command type and parameters
            /// to the provided command.
            /// </summary>
            /// <param name="command">the OracleCommand to be prepared</param>
            /// <param name="connection">a valid OracleConnection, on which to execute this command</param>
            /// <param name="transaction">a valid OracleTransaction, or 'null'</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <param name="commandParameters">an array of OracleParameters to be associated with the command or 'null' if no parameters are required</param>
            private static void PrepareCommand(OracleCommand command, OracleConnection connection, OracleTransaction transaction, CommandType commandType, string commandText, OracleParameter[] commandParameters)
            {
                //if the provided connection is not open, we will open it
                if (connection.State != ConnectionState.Open)
                {
                    connection.Open();
                }

                //associate the connection with the command
                command.Connection = connection;

                //set the command text (stored procedure name or Oracle statement)
                command.CommandText = commandText;

                //if we were provided a transaction, assign it.
                if (transaction != null)
                {
                    command.Transaction = transaction;
                }

                //set the command type
                command.CommandType = commandType;

                //attach the command parameters if they are provided
                if (commandParameters != null)
                {
                    AttachParameters(command, commandParameters);
                }

                return;
            }


            #endregion private utility methods & constructors

            #region ExecuteNonQuery

            /// <summary>
            /// Execute an OracleCommand (that returns no resultset and takes no parameters) against the database specified in
            /// the connection string.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteNonQuery(connectionString, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns no resultset) against the database specified in the connection string
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create & open an OracleConnection, and dispose of it after we are done.
                using (OracleConnection cn = new OracleConnection(connectionString))
                {
                    cn.Open();

                    //call the overload that takes a connection in place of the connection string
                    return ExecuteNonQuery(cn, commandType, commandText, commandParameters);
                }
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns no resultset) against the database specified in
            /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns no resultset and takes no parameters) against the provided OracleConnection.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(OracleConnection connection, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteNonQuery(connection, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns no resultset) against the specified OracleConnection
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(OracleConnection connection, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, connection, (OracleTransaction)null, commandType, commandText, commandParameters);

                //finally, execute the command.
                return cmd.ExecuteNonQuery();
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns no resultset) against the specified OracleConnection
            /// using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(OracleConnection connection, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns no resultset and takes no parameters) against the provided OracleTransaction.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(OracleTransaction transaction, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteNonQuery(transaction, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns no resultset) against the specified OracleTransaction
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

                //finally, execute the command.
                return cmd.ExecuteNonQuery();
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns no resultset) against the specified
            /// OracleTransaction using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(OracleTransaction transaction, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteNonQuery

            #region ExecuteDataSet

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset and takes no parameters) against the database specified in
            /// the connection string.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteDataset(connectionString, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset) against the database specified in the connection string
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create & open an OracleConnection, and dispose of it after we are done.
                using (OracleConnection cn = new OracleConnection(connectionString))
                {
                    cn.Open();

                    //call the overload that takes a connection in place of the connection string
                    return ExecuteDataset(cn, commandType, commandText, commandParameters);
                }
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a resultset) against the database specified in
            /// the conneciton string using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset and takes no parameters) against the provided OracleConnection.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(OracleConnection connection, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteDataset(connection, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset) against the specified OracleConnection
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(OracleConnection connection, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, connection, (OracleTransaction)null, commandType, commandText, commandParameters);

                //create the DataAdapter & DataSet
                OracleDataAdapter da = new OracleDataAdapter(cmd);
                DataSet ds = new DataSet();
                ds.Locale = System.Globalization.CultureInfo.InvariantCulture;
                //fill the DataSet using default values for DataTable names, etc.
                da.Fill(ds);

                //return the dataset
                return ds;
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a resultset) against the specified OracleConnection
            /// using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(OracleConnection connection, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset and takes no parameters) against the provided OracleTransaction.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(OracleTransaction transaction, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteDataset(transaction, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset) against the specified OracleTransaction
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

                //create the DataAdapter & DataSet
                OracleDataAdapter da = new OracleDataAdapter(cmd);
                DataSet ds = new DataSet();
                ds.Locale = System.Globalization.CultureInfo.InvariantCulture;
                //fill the DataSet using default values for DataTable names, etc.
                da.Fill(ds);

                //return the dataset
                return ds;
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a resultset) against the specified
            /// OracleTransaction using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>a dataset containing the resultset generated by the command</returns>
            public static DataSet ExecuteDataset(OracleTransaction transaction, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteDataSet

            #region ExecuteReader

            /// <summary>
            /// this enum is used to indicate weather the connection was provided by the caller, or created by OracleHelper, so that
            /// we can set the appropriate CommandBehavior when calling ExecuteReader()
            /// </summary>
            private enum OracleConnectionOwnership
            {
                /// <summary>Connection is owned and managed by OracleHelper</summary>
                Internal,
                /// <summary>Connection is owned and managed by the caller</summary>
                External
            }


            /// <summary>
            /// Create and prepare an OracleCommand, and call ExecuteReader with the appropriate CommandBehavior.
            /// </summary>
            /// <remarks>
            /// If we created and opened the connection, we want the connection to be closed when the DataReader is closed.
            ///
            /// If the caller provided the connection, we want to leave it to them to manage.
            /// </remarks>
            /// <param name="connection">a valid OracleConnection, on which to execute this command</param>
            /// <param name="transaction">a valid OracleTransaction, or 'null'</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <param name="commandParameters">an array of OracleParameters to be associated with the command or 'null' if no parameters are required</param>
            /// <param name="connectionOwnership">indicates whether the connection parameter was provided by the caller, or created by OracleHelper</param>
            /// <returns>OracleDataReader containing the results of the command</returns>
            private static OracleDataReader ExecuteReader(OracleConnection connection, OracleTransaction transaction, CommandType commandType, string commandText, OracleParameter[] commandParameters, OracleConnectionOwnership connectionOwnership)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters);

                //create a reader
                OracleDataReader dr;

                // call ExecuteReader with the appropriate CommandBehavior
                if (connectionOwnership == OracleConnectionOwnership.External)
                {
                    dr = cmd.ExecuteReader();
                }
                else
                {
                    dr = cmd.ExecuteReader((CommandBehavior)((int)CommandBehavior.CloseConnection));
                }

                return (OracleDataReader)dr;
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset and takes no parameters) against the database specified in
            /// the connection string.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteReader(connectionString, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset) against the database specified in the connection string
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create & open an OraclebConnection
                OracleConnection cn = new OracleConnection(connectionString);
                cn.Open();

                try
                {
                    //call the private overload that takes an internally owned connection in place of the connection string
                    return ExecuteReader(cn, null, commandType, commandText, commandParameters, OracleConnectionOwnership.Internal);
                }
                catch
                {
                    //if we fail to return the OracleDataReader, we need to close the connection ourselves
                    cn.Close();
                    throw;
                }
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a resultset) against the database specified in
            /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset and takes no parameters) against the provided OracleConnection.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(OracleConnection connection, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteReader(connection, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset) against the specified OracleConnection
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(OracleConnection connection, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //pass through the call to the private overload using a null transaction value and an externally owned connection
                return ExecuteReader(connection, (OracleTransaction)null, commandType, commandText, commandParameters, OracleConnectionOwnership.External);
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a resultset) against the specified OracleConnection
            /// using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(OracleConnection connection, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset and takes no parameters) against the provided OracleTransaction.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param> 
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(OracleTransaction transaction, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteReader(transaction, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a resultset) against the specified OracleTransaction
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///   OracleDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or PL/SQL command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //pass through to private overload, indicating that the connection is owned by the caller
                return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, OracleConnectionOwnership.External);
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a resultset) against the specified
            /// OracleTransaction using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  OracleDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an OracleDataReader containing the resultset generated by the command</returns>
            public static OracleDataReader ExecuteReader(OracleTransaction transaction, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteReader

            #region ExecuteScalar

            /// <summary>
            /// Execute an OracleCommand (that returns a 1x1 resultset and takes no parameters) against the database specified in
            /// the connection string.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-Oracle command</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteScalar(connectionString, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a 1x1 resultset) against the database specified in the connection string
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-Oracle command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create & open an OracleConnection, and dispose of it after we are done.
                using (OracleConnection cn = new OracleConnection(connectionString))
                {
                    cn.Open();

                    //call the overload that takes a connection in place of the connection string
                    return ExecuteScalar(cn, commandType, commandText, commandParameters);
                }
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a 1x1 resultset) against the database specified in
            /// the conneciton string using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a 1x1 resultset and takes no parameters) against the provided OracleConnection.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-Oracle command</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(OracleConnection connection, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteScalar(connection, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a 1x1 resultset) against the specified OracleConnection
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-OleDb command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(OracleConnection connection, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, connection, (OracleTransaction)null, commandType, commandText, commandParameters);

                //execute the command & return the results
                return cmd.ExecuteScalar();
            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a 1x1 resultset) against the specified OracleConnection
            /// using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);
            /// </remarks>
            /// <param name="connection">a valid OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(OracleConnection connection, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a 1x1 resultset and takes no parameters) against the provided OracleTransaction.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-OleDb command</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(OracleTransaction transaction, CommandType commandType, string commandText)
            {
                //pass through the call providing null for the set of OracleParameters
                return ExecuteScalar(transaction, commandType, commandText, (OracleParameter[])null);
            }

            /// <summary>
            /// Execute an OracleCommand (that returns a 1x1 resultset) against the specified OracleTransaction
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new OracleParameter("@prodid", 24));
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-OleDb command</param>
            /// <param name="commandParameters">an array of OracleParameters used to execute the command</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
            {
                //create a command and prepare it for execution
                OracleCommand cmd = new OracleCommand();
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

                //execute the command & return the results
                return cmd.ExecuteScalar();

            }

            /// <summary>
            /// Execute a stored procedure via an OracleCommand (that returns a 1x1 resultset) against the specified
            /// OracleTransaction using the provided parameter values.  This method will query the database to discover the parameters for the
            /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
            /// </summary>
            /// <remarks>
            /// This method provides no access to output parameters or the stored procedure's return value parameter.
            ///
            /// e.g.: 
            ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);
            /// </remarks>
            /// <param name="transaction">a valid OracleTransaction</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="parameterValues">an array of objects to be assigned as the input values of the stored procedure</param>
            /// <returns>an object containing the value in the 1x1 resultset generated by the command</returns>
            public static object ExecuteScalar(OracleTransaction transaction, string spName, params object[] parameterValues)
            {
                //if we got parameter values, we need to figure out where they go
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    //pull the parameters for this stored procedure from the parameter cache (or discover them & populet the cache)
                    OracleParameter[] commandParameters = OracleHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                    //assign the provided values to these parameters based on parameter order
                    AssignParameterValues(commandParameters, parameterValues);

                    //call the overload that takes an array of OracleParameters
                    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                //otherwise we can just call the SP without params
                else
                {
                    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteScalar
        }

        /// <summary>
        /// OracleHelperParameterCache provides functions to leverage a static cache of procedure parameters, and the
        /// ability to discover parameters for stored procedures at run-time.
        /// </summary>
        public sealed class OracleHelperParameterCache
        {
            #region private methods, variables, and constructors

            //Since this class provides only static methods, make the default constructor private to prevent
            //instances from being created with "new OracleHelperParameterCache()".
            private OracleHelperParameterCache() { }

            private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

            /// <summary>
            /// resolve at run-time the appropriate set of OracleParameters for a stored procedure
            /// </summary>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="includeReturnValueParameter">whether or not to include ther return value parameter</param>
            /// <returns></returns>
            private static OracleParameter[] DiscoverSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
            {
                using (OracleConnection cn = new OracleConnection(connectionString))
                using (OracleCommand cmd = new OracleCommand(spName, cn))
                {
                    cn.Open();
                    cmd.CommandType = CommandType.StoredProcedure;

                    OracleCommandBuilder.DeriveParameters(cmd);

                    if (!includeReturnValueParameter)
                    {
                        if (ParameterDirection.ReturnValue == cmd.Parameters[0].Direction)
                            cmd.Parameters.RemoveAt(0);
                    }

                    OracleParameter[] discoveredParameters = new OracleParameter[cmd.Parameters.Count];

                    cmd.Parameters.CopyTo(discoveredParameters, 0);

                    return discoveredParameters;
                }
            }

            //deep copy of cached OracleParameter array
            private static OracleParameter[] CloneParameters(OracleParameter[] originalParameters)
            {
                OracleParameter[] clonedParameters = new OracleParameter[originalParameters.Length];

                for (int i = 0, j = originalParameters.Length; i < j; i++)
                {
                    clonedParameters[i] = (OracleParameter)((ICloneable)originalParameters[i]).Clone();
                }

                return clonedParameters;
            }

            #endregion private methods, variables, and constructors

            #region caching functions

            /// <summary>
            /// add parameter array to the cache
            /// </summary>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandText">the stored procedure name or T-OleDb command</param>
            /// <param name="commandParameters">an array of OracleParameters to be cached</param>
            public static void CacheParameterSet(string connectionString, string commandText, params OracleParameter[] commandParameters)
            {
                string hashKey = connectionString + ":" + commandText;

                paramCache[hashKey] = commandParameters;
            }

            /// <summary>
            /// retrieve a parameter array from the cache
            /// </summary>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="commandText">the stored procedure name or T-OleDb command</param>
            /// <returns>an array of OracleParameters</returns>
            public static OracleParameter[] GetCachedParameterSet(string connectionString, string commandText)
            {
                string hashKey = connectionString + ":" + commandText;

                OracleParameter[] cachedParameters = (OracleParameter[])paramCache[hashKey];

                if (cachedParameters == null)
                {
                    return null;
                }
                else
                {
                    return CloneParameters(cachedParameters);
                }
            }

            #endregion caching functions

            #region Parameter Discovery Functions

            /// <summary>
            /// Retrieves the set of OracleParameters appropriate for the stored procedure
            /// </summary>
            /// <remarks>
            /// This method will query the database for this information, and then store it in a cache for future requests.
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <returns>an array of OracleParameters</returns>
            public static OracleParameter[] GetSpParameterSet(string connectionString, string spName)
            {
                return GetSpParameterSet(connectionString, spName, false);
            }

            /// <summary>
            /// Retrieves the set of OracleParameters appropriate for the stored procedure
            /// </summary>
            /// <remarks>
            /// This method will query the database for this information, and then store it in a cache for future requests.
            /// </remarks>
            /// <param name="connectionString">a valid connection string for an OracleConnection</param>
            /// <param name="spName">the name of the stored procedure</param>
            /// <param name="includeReturnValueParameter">a bool value indicating whether the return value parameter should be included in the results</param>
            /// <returns>an array of OracleParameters</returns>
            public static OracleParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
            {
                string hashKey = connectionString + ":" + spName + (includeReturnValueParameter ? ":include ReturnValue Parameter" : "");

                OracleParameter[] cachedParameters;

                cachedParameters = (OracleParameter[])paramCache[hashKey];

                if (cachedParameters == null)
                {
                    cachedParameters = (OracleParameter[])(paramCache[hashKey] = DiscoverSpParameterSet(connectionString, spName, includeReturnValueParameter));
                }

                return CloneParameters(cachedParameters);
            }

            #endregion Parameter Discovery Functions

        }

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  • 原文地址:https://www.cnblogs.com/nogodsend/p/2196930.html
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