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/* -*- c++ -*-
* __BEGIN_COPYRIGHT
* SimpleDB API
*
* Copyright (C) 2005 Eminence Technology Pty Ltd
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You can view the GNU Lesser General Public Licence at
* http://www.gnu.org/licenses/lgpl.html or you can write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Eminence Technology Pty Ltd can be contacted by writing to
* Eminence Technology, PO Box 118, Moorooka QLD 4105, Australia.
* Alternatively, you may email opensource [at] eminence [dot] com [dot] au
* __END_COPYRIGHT
*/
#ifndef __SIMPLEDB_COLUMN_H_
#define __SIMPLEDB_COLUMN_H_ 1
#include <sql.h>
#include <sqlext.h>
#include <iostream>
#include <string>
#include "Exception.h" // for Database::Exception
namespace SimpleDB {
/** The abstract base class for the SimpleDB types.
* This type contains the actual data as well as meta-data.
*/
class Column {
public:
/** Exception class.
* Thrown when a column's value is requested but the column hasn't been
* bound
*/
class UnboundException : public Exception {
public:
/** Constructor used when creating a new UnboundException object.
*/
UnboundException() : Exception("Column is not bound.") {};
};
/** Tests if the current value is NULL
*
* @return True if the value is NULL.
*/
virtual bool isNull();
/** This abstract function is called by Query when the Query.bind function
* is invoked.
* This function has an implementation that handles making sure columns are
* bound. This function should be called by any derived objects.
*
* @param statementHandle The statementHandle columns are being bound to
* @param columnNumber The column number to bind this column to..
*/
virtual void bind(SQLHSTMT statementHandle, int columnNumber) = 0;
/** Function called to write a column value to the output stream.
* This function is implemented by each column type to write the value
* in a suitable form to the output stream.
*
* @param oStream Output stream object.
* @return Output stream object to which data was written.
*/
virtual std::ostream& oStream(std::ostream& oStream) = 0;
/** A virtual destructor that can be overridden if required.
* This can be used, for example, to deallocate memory.
*/
virtual ~Column() {};
/** Constructor used to set initial value of columnBound variable.
*/
Column();
/** This method is to be called by all derived classes to make sure
* the column was bound. It will cause an exception to be thrown if the
* column wasn't bound.
*/
void value();
protected:
/** The lengthOrIndex variable to be sent to the SQLBindCol function.
*/
SQLINTEGER lengthOrIndex;
/** Indicates weather this column has been bound to a query.
*/
bool bound;
/** Name that can be used
*
*/
std::string name;
};
/** Class representing string values.
*/
class StringColumn : public Column {
public:
/** Constructor to allocate memory for this column.
* This function will throw an Exception if the memory cannot be allocated.
*
* @param bufferSize The maximum number of bytes the value will hold.
*/
StringColumn(const int bufferSize);
/** Destructor frees allocated memory.
*/
~StringColumn();
std::ostream& oStream(std::ostream& oStream);
void bind(SQLHSTMT statementHandle, int columnNumber);
/** Returns the string value of this object.
*
* @return The string value.
*/
std::string value();
private:
long bufferSize;
char * buffer;
};
/** Class representing long values.
*/
class LongColumn : public Column {
public:
std::ostream& oStream(std::ostream& oStream);
void bind(SQLHSTMT statementHandle, int columnNumber);
/** Used to retrieve the value of this column.
*
* @return The long value of this column.
*/
long value() {Column::value(); if(isNull()) return 0; else return colValue;};
private:
/** The long column value
*/
long colValue;
};
/** Class representing bool values.
*/
class BoolColumn : public Column {
public:
std::ostream& oStream(std::ostream& oStream);
void bind(SQLHSTMT statementHandle, int columnNumber);
/** Used to retrieve the value of this column.
*
* @return The long value of this column.
*/
bool value() ;
private:
/** The long column value
*/
unsigned char colValue;
};
}
inline
std::ostream& operator<<(std::ostream& strm, SimpleDB::Column& col) {
return col.oStream(strm);
}
#endif
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