DatabaseStatement.h

/*
╔══════════════════════════════════════════════════════════════════════════════╗
║                        SIMPLY POWERFUL TOOLKIT (SPTK)                        ║
╟──────────────────────────────────────────────────────────────────────────────╢
║  copyright            © 1999-2022 Alexey Parshin. All rights reserved.       ║
║  email                alexeyp@gmail.com                                      ║
╚══════════════════════════════════════════════════════════════════════════════╝
┌──────────────────────────────────────────────────────────────────────────────┐
│   This library is free software; you can redistribute it and/or modify it    │
│   under the terms of the GNU Library General Public License as published by  │
│   the Free Software Foundation; either version 2 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 Library   │
│   General Public License for more details.                                   │
│                                                                              │
│   You should have received a copy of the GNU Library General Public License  │
│   along with this library; if not, write to the Free Software Foundation,    │
│   Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.               │
│                                                                              │
│   Please report all bugs and problems to alexeyp@gmail.com.                  │
└──────────────────────────────────────────────────────────────────────────────┘
*/
 
#pragma once
 
#include <sptk5/db/QueryParameterList.h>
 
namespace sptk {
 
template<class Connection, class Statement>
class DatabaseStatement
{
public:
    Connection* connection() const
    {
        return m_connection;
    }
 
    void statement(Statement* stmt)
    {
        m_statement = stmt;
    }
 
    Statement* statement() const
    {
        return m_statement;
    }
 
    explicit DatabaseStatement(Connection* connection)
        : m_connection(connection)
    {
    }
 
    virtual ~DatabaseStatement() = default;
 
    Statement* stmt() const
    {
        return m_statement;
    }
 
    virtual void enumerateParams(QueryParameterList& queryParams)
    {
        queryParams.enumerate(m_enumeratedParams);
        m_state.outputParameterCount = 0;
 
        for (auto parameter: m_enumeratedParams)
        {
            if (parameter->isOutput())
                ++m_state.outputParameterCount;
        }
    }
 
    CParamVector& enumeratedParams()
    {
        return m_enumeratedParams;
    }
 
    size_t outputParameterCount() const
    {
        return m_state.outputParameterCount;
    }
 
    virtual void setParameterValues() = 0;
 
    virtual void execute(bool inTransaction) = 0;
 
    virtual void close() = 0;
 
    virtual void fetch() = 0;
 
    bool eof() const
    {
        return m_state.eof;
    }
 
    unsigned colCount() const
    {
        return m_state.columnCount;
    }
 
protected:
    struct State {
        unsigned columnCount : 12;
 
        bool eof : 1;
 
        bool transaction : 1;
 
        unsigned outputParameterCount : 1;
    };
 
    State& state()
    {
        return m_state;
    }
 
private:
    Connection* m_connection {nullptr}; 
    Statement* m_statement {nullptr};   
    State m_state {};                   
    CParamVector m_enumeratedParams;    
};
 
} // namespace sptk