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/*
* query.h
*
* Copyright (C) 2009 Tim Marston <edam@waxworlds.org>
*
* This file is part of sqlite3cc (hereafter referred to as "this program").
* See http://www.waxworlds.org/edam/software/sqlite3cc for more information.
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
* This program 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 should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef SQLITE3CC_QUERY_H_
#define SQLITE3CC_QUERY_H_
#include <boost/iterator/iterator_facade.hpp>
#include <sqlite3cc/basic_statement.h>
#include <sqlite3cc/row.h>
namespace sqlite
{
class query
:
public basic_statement
{
//______________________________________________________________________________
// instantiation
public:
/**
* Constructor that provides a database upon which to act and the SQL
* query to execute.
* @param database a reference to a database
* @param sql an SQL statement in UTF-8
*/
explicit query(
database &database,
const std::string &sql );
/**
* Constructor that provides a database upon which to act.
* @param database a reference to a database
* @param sql an SQL statement in UTF-8
*/
explicit query(
database &database );
//______________________________________________________________________________
// public interface
public:
/**
* Prepare an SQL statement.
* @param sql an SQL statement in UTF-8
* @returns an sqlite error code
* @see sqlite3_prepare_v2()
*/
virtual int prepare(
const std::string &sql );
/**
* Peform a step() and return row object that can be used to retrieve the
* results.
* @return a row object
*/
row step();
/**
* Get the number of columns in the results
* @see sqlite3_column_count()
*/
unsigned int column_count();
/**
* Get the name of a column in the results
* @param index column index
* @see sqlite3_column_name()
*/
const std::string column_name(
unsigned int index );
/**
* Query iterator which can be used to obtain rows
*/
class iterator
:
public boost::iterator_facade< iterator, row,
boost::single_pass_traversal_tag, row >
{
public:
iterator();
explicit iterator( query &query, bool valid );
private:
friend class boost::iterator_core_access;
row dereference() const;
void increment();
bool equal( iterator const &other ) const;
/** is this iterator still pointing to a valid row? */
bool _valid;
/** the query */
query &_query;
};
/**
* Return an iterator to the initial row. Note that creating an iterator
* causes step() to be called, so it should only be called to begin
* iterating over the rows and not for comparison.
* @return a query iterator
*/
iterator begin();
/**
* Return an iterator to after the last row (i.e., an invalid row).
*/
iterator end();
//______________________________________________________________________________
// implementation
private:
/** next row index */
unsigned long long _next_row;
};
} // namespace sqlite
#endif /* SQLITE3CC_QUERY_H_ */
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