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Column.h
//
// Column.h
//
// $Id: //poco/1.4/Data/include/Poco/Data/Column.h#1 $
//
// Library: Data
// Package: DataCore
// Module:  Column
//
// Definition of the Column class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Data_Column_INCLUDED
#define Data_Column_INCLUDED


#include "Poco/Data/Data.h"
#include "Poco/Data/MetaColumn.h"
#include "Poco/SharedPtr.h"
#include <vector>


namespace Poco {
namespace Data {


template <class T>
00054 class Column
      /// Column class is column data container.
      /// Data (a pointer to vector of contained values) is assigned to the class 
      /// through either constructor or set() member function.
      /// Construction with null pointer is not allowed.
      /// This class owns the data assigned to it and deletes the storage on destruction.
{
public:
      typedef std::vector<T> DataVec;
      typedef typename DataVec::const_iterator Iterator;
      typedef typename DataVec::size_type Size;

      Column(const MetaColumn& metaColumn, std::vector<T>* pData): _metaColumn(metaColumn), _pData(pData)
            /// Creates the Column.
      {
            poco_check_ptr (_pData);
      }

      Column(const Column& col): _metaColumn(col._metaColumn), _pData(col._pData)
            /// Creates the Column.
      {
      }

00077       ~Column()
            /// Destroys the Column.
      {
      }

00082       Column& operator = (const Column& col)
            /// Assignment operator.
      {
            Column tmp(col);
            swap(tmp);
            return *this;
      }

00090       void swap(Column& other)
            /// Swaps the column with another one.
      {
            std::swap(_metaColumn, other._metaColumn);
            std::swap(_pData, other._pData);
      }

00097       DataVec& data()
            /// Returns reference to contained data.
      {
            return *_pData;
      }

00103       const T& value(std::size_t row) const
            /// Returns the field value in specified row.
      {
            try
            {
                  return _pData->at(row);
            }
            catch (std::out_of_range& ex)
            { 
                  throw RangeException(ex.what()); 
            }
      }

00116       const T& operator [] (std::size_t row) const
            /// Returns the field value in specified row.
      {
            return value(row);
      }

00122       Size rowCount() const
            /// Returns number of rows.
      {
            return _pData->size();
      }

00128       void reset()
            /// Clears and shrinks the storage.
      {
            std::vector<T>().swap(*_pData);
      }

00134       const std::string& name() const
            /// Returns column name.
      {
            return _metaColumn.name();
      }

00140       std::size_t length() const
            /// Returns column maximum length.
      {
            return _metaColumn.length();
      }

00146       std::size_t precision() const
            /// Returns column precision.
            /// Valid for floating point fields only (zero for other data types).
      {
            return _metaColumn.precision();
      }

00153       std::size_t position() const
            /// Returns column position.
      {
            return _metaColumn.position();
      }

00159       MetaColumn::ColumnDataType type() const
            /// Returns column type.
      {
            return _metaColumn.type();
      }

00165       Iterator begin() const
            /// Returns iterator pointing to the beginning of data storage vector.
      {
            return _pData->begin();
      }

00171       Iterator end() const
            /// Returns iterator pointing to the end of data storage vector.
      {
            return _pData->end();
      }

private:
      Column();

      MetaColumn               _metaColumn;
      Poco::SharedPtr<DataVec> _pData;
};


} } // namespace Poco::Data


#endif // Data_Column_INCLUDED


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