sql.cpp

/***************************************************************************
 *   Copyright (C) 2006 by Graeme Foster                                   *
 *   email    foster.graeme@gmail.com                                      *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <QMessageBox>
#include <iostream>

#include "sql.h"

// Initialisation of static member variables
QString * sql::DefaultConnectionName = new QString("guestConn");
sql* sql::_instance = 0;

sql * sql::Instance()
{
        if (_instance == 0)
        {
                _instance = new sql;
        }
        return _instance;
}

sql::sql ()
{
        lastDBConnName = QString();
        result = 0;
}

void sql::initConn(const QString & uName
                                                ,const QString & dbName
                                                ,const QString & password
                                                ,const QString & connName
                                                ,const QString & host
                                                ,const QString & connType
                                                )
{       
        QSqlDatabase dbConn = QSqlDatabase::addDatabase(connType,connName);
        
        dbConn.setDatabaseName(dbName);
        dbConn.setUserName(uName);
        dbConn.setPassword(password);
        dbConn.setHostName(host);
        
        if (!dbConn.open())
        {
                throw sqlE(dbConn, "Failed to log on to the Database");
        }
        lastDBConnName = connName;
}

int sql::prepare(const QString & functionName
                ,int paramCnt
                ,const QString & connName)
{
        QString paramList = "?";
        for (int cnt = 1; cnt < paramCnt; cnt++)
        {
                paramList += ", ?";
        }
        QString command = "SELECT " + functionName + "(" + paramList + ")";
        QString dbConn;
        if (connName=="")
                dbConn = lastDBConnName;
        else
        {
                dbConn = connName;
                lastDBConnName = dbConn;
        }
        QSqlQuery * preparedStmt = new QSqlQuery (QSqlDatabase::database(dbConn));
        preparedStmt->prepare(command);
        queryList.append(preparedStmt);
        activeQuery = preparedStmt;
        return queryList.size()-1;
}

int sql::prepare(const QString & command
                ,const QString & connName)
{
        QString dbConn;
        if (connName=="")
                dbConn = lastDBConnName;
        else
        {
                dbConn = connName;
                lastDBConnName = dbConn;
        }
        QSqlQuery * preparedStmt = new QSqlQuery (QSqlDatabase::database(dbConn));
        preparedStmt->prepare(command);
        queryList.append(preparedStmt);
        activeQuery = preparedStmt;
        return queryList.size()-1;
}


void sql::bind(int posn
              ,QVariant value
              ,int qID)
{
        if (qID >= 0 && qID < queryList.size())
        {
                activeQuery = queryList.at(qID);
        }
        activeQuery->bindValue(posn, value);
}

bool sql::query(int qID)
{
        if (qID >= 0 && qID < queryList.size())
        {
                activeQuery = queryList.at(qID);
        }
        result = new QSqlQuery(*activeQuery);
        bool success = result->exec();
        if  (success == false)
                throw sqlE(QSqlDatabase::database(lastDBConnName), "Query Error: \"" + result->lastQuery() +"\"");
        return success;
}

bool sql::first()
{
        if (result == 0)
                throw sqlE(QSqlDatabase::database(lastDBConnName));
        bool success = result->first();
        return success;
}

bool sql::next ()
{
        if (result == 0)
                throw sqlE(QSqlDatabase::database(lastDBConnName));
        bool success = result->next();
        return success;
}

bool sql::last ()
{
        if (result == 0)
                throw sqlE(QSqlDatabase::database(lastDBConnName));
        bool success = result->last();
        return success;
}

QVariant sql::get(int index)
{
        if (result == 0)
                throw sqlE(QSqlDatabase::database(lastDBConnName));
        return result->value(index);
}

QVariant sql::getFirst(int index)
{
        first();
        return get(index);
}

QVariant sql::getNext(int index)
{
        next();
        return get(index);
}

void sql::dump()
{
        std::cout << "The number of records is:" << result->size() << std::endl;
}

// SQL Exception member functions
sqlE::sqlE(const QSqlDatabase & dbConn
                         ,const QString & type)
{
        ErrorType = type;
        QSqlError errorObj = dbConn.lastError();
        ErrorMessage = errorObj.text() + "\n" + type + "\n" + errorObj.driverText() + "\n" + errorObj.databaseText ();
}

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