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RecordSet.h
//
// RecordSet.h
//
// $Id: //poco/1.4/Data/include/Poco/Data/RecordSet.h#1 $
//
// Library: Data
// Package: DataCore
// Module:  RecordSet
//
// Definition of the RecordSet 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_RecordSet_INCLUDED
#define Data_RecordSet_INCLUDED


#include "Poco/Data/Data.h"
#include "Poco/Data/Extraction.h"
#include "Poco/Data/Statement.h"
#include "Poco/Data/BLOB.h"
#include "Poco/String.h"
#include "Poco/DynamicAny.h"
#include "Poco/Exception.h"


namespace Poco {
namespace Data {


00056 class Data_API RecordSet: private Statement
      /// RecordSet provides access to data returned from a query.
      /// Data access indexes (row and column) are 0-based, as usual in C++.
      /// 
      /// Recordset provides navigation methods to iterate through the
      /// recordset, retrieval methods to extract data, and methods
      /// to get metadata (type, etc.) about columns.
      ///
      /// To work with a RecordSet, first create a Statement, execute it, and
      /// create the RecordSet from the Statement, as follows:
      ///
      ///     Statement select(session);
      ///     select << "SELECT * FROM Person";
      ///     select.execute();
      ///     RecordSet rs(select);
      ///
      /// The number of rows in the RecordSet can be limited by specifying
      /// a limit for the Statement.
{
public:
      explicit RecordSet(const Statement& rStatement);
            /// Creates the RecordSet.

      ~RecordSet();
            /// Destroys the RecordSet.

      Statement& operator = (const Statement& stmt);
            /// Assignment operator.

      std::size_t rowCount() const;
            /// Returns the number of rows in the recordset.

      std::size_t columnCount() const;
            /// Returns the number of rows in the recordset.

      template<class T>
00092       const Column<T>& column(const std::string& name) const
            /// Returns the reference to the first Column with the specified name.
      {
            return column<T>(columnPosition<T>(name));
      }

      template<class T>
00099       const Column<T>& column(std::size_t pos) const
            /// Returns the reference to column at specified location.
      {
            typedef const InternalExtraction<T>* ExtractionVecPtr;

            const AbstractExtractionVec& rExtractions = extractions();

            std::size_t s = rExtractions.size();
            if (0 == s || pos >= s)
                  throw RangeException(format("Invalid column index: %z", pos));
            
            ExtractionVecPtr pExtraction = dynamic_cast<ExtractionVecPtr>(rExtractions[pos].get());

            if (pExtraction)
            {
                  return pExtraction->column();
            }
            else 
            {
                  throw Poco::BadCastException(format("Type cast failed!\nColumn: %z\nTarget type:\t%s",  
                        pos,
                        std::string(typeid(T).name())));
            }
      }

      template<class T>
00125       const T& value(std::size_t col, std::size_t row) const
            /// Returns the reference to data value at [col, row] location.
      {
            return column<T>(col).value(row);
      }

      template<class T>
00132       const T& value(const std::string& name, std::size_t row) const
            /// Returns the reference to data value at named column, row location.
      {
            return column<T>(name).value(row);
      }

      DynamicAny value(std::size_t col, std::size_t row) const;
            /// Returns the reference to data value at column, row location.

      DynamicAny value(const std::string& name, std::size_t row) const;
            /// Returns the reference to data value at named column, row location.

      bool moveFirst();
            /// Moves the row cursor to the first row.
            ///
            /// Returns true if there is at least one row in the RecordSet,
            /// false otherwise.

      bool moveNext();
            /// Moves the row cursor to the next row.
            ///
            /// Returns true if the row is available, or false
            /// if the end of the record set has been reached and
            /// no more rows are available.

      bool movePrevious();
            /// Moves the row cursor to the previous row.
            ///
            /// Returns true if the row is available, or false
            /// if there are no more rows available.

      bool moveLast();
            /// Moves the row cursor to the last row.
            ///
            /// Returns true if there is at least one row in the RecordSet,
            /// false otherwise.

      DynamicAny value(const std::string& name);
            /// Returns the value in the named column of the current row.

      DynamicAny value(std::size_t index);
            /// Returns the value in the given column of the current row.

      DynamicAny operator [] (const std::string& name);
            /// Returns the value in the named column of the current row.

      DynamicAny operator [] (std::size_t index);
            /// Returns the value in the named column of the current row.

      MetaColumn::ColumnDataType columnType(std::size_t pos) const;
            /// Returns the type for the column at specified position.

      MetaColumn::ColumnDataType columnType(const std::string& name) const;
            /// Returns the type for the column with specified name.

      const std::string& columnName(std::size_t pos) const;
            /// Returns column name for the column at specified position.

      std::size_t columnLength(std::size_t pos) const;
            /// Returns column maximum length for the column at specified position.

      std::size_t columnLength(const std::string& name) const;
            /// Returns column maximum length for the column with specified name.

      std::size_t columnPrecision(std::size_t pos) const;
            /// Returns column precision for the column at specified position.
            /// Valid for floating point fields only (zero for other data types).

      std::size_t columnPrecision(const std::string& name) const;
            /// Returns column precision for the column with specified name.
            /// Valid for floating point fields only (zero for other data types).

private:
      RecordSet();

      template<class T>
00208       std::size_t columnPosition(const std::string& name) const
            /// Returns the position of the column with specified name.
      {
            typedef const InternalExtraction<T>* ExtractionVecPtr;

            const AbstractExtractionVec& rExtractions = extractions();
            AbstractExtractionVec::const_iterator it = rExtractions.begin();
            AbstractExtractionVec::const_iterator end = rExtractions.end();
            
            for (; it != end; ++it)
            {
                  ExtractionVecPtr pExtraction = dynamic_cast<ExtractionVecPtr>(it->get());

                  if (pExtraction)
                  {
                        const Column<T>& col = pExtraction->column();
                        if (0 == Poco::icompare(name, col.name()))
                              return col.position();
                  }
            }

            throw NotFoundException(format("Unknown column name: %s", name));
      }

      std::size_t _currentRow;
};


///
/// inlines
///
00239 inline std::size_t RecordSet::rowCount() const
{
      poco_assert (extractions().size());
      return extractions()[0].get()->numOfRowsHandled();
}


00246 inline std::size_t RecordSet::columnCount() const
{
      return extractions().size();
}


00252 inline Statement& RecordSet::operator = (const Statement& stmt)
{
      _currentRow = 0;
      return Statement::operator = (stmt);
}


00259 inline DynamicAny RecordSet::value(const std::string& name)
{
      return value(name, _currentRow);
}


00265 inline DynamicAny RecordSet::value(std::size_t index)
{
      return value(index, _currentRow);
}


00271 inline DynamicAny RecordSet::operator [] (const std::string& name)
{
      return value(name, _currentRow);
}


00277 inline DynamicAny RecordSet::operator [] (std::size_t index)
{
      return value(index, _currentRow);
}


00283 inline MetaColumn::ColumnDataType RecordSet::columnType(std::size_t pos)const
{
      return metaColumn(static_cast<UInt32>(pos)).type();
}


00289 inline MetaColumn::ColumnDataType RecordSet::columnType(const std::string& name)const
{
      return metaColumn(name).type();
}


00295 inline const std::string& RecordSet::columnName(std::size_t pos) const
{
      return metaColumn(static_cast<UInt32>(pos)).name();
}


00301 inline std::size_t RecordSet::columnLength(std::size_t pos) const
{
      return metaColumn(static_cast<UInt32>(pos)).length();
}


00307 inline std::size_t RecordSet::columnLength(const std::string& name)const
{
      return metaColumn(name).length();
}


00313 inline std::size_t RecordSet::columnPrecision(std::size_t pos) const
{
      return metaColumn(static_cast<UInt32>(pos)).precision();
}


00319 inline std::size_t RecordSet::columnPrecision(const std::string& name)const
{
      return metaColumn(name).precision();
}


} } // namespace Poco::Data


#endif // Data_RecordSet_INCLUDED

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