Get Started with QT and Embedded FireBird

#include "stdafx.h"
#include "FireBirdDatabase.h"

#include "ibase.h"
#include "iberror.h"

using namespace Model;

QString FireBirdDatabase::qtIBaseDriverName_ = "QIBASE";
QString FireBirdDatabase::connectionString_ = "server type=Embedded; auto_commit=True; auto_commit_level=4096; connection lifetime=1; DataBase=\"%1\"";

#ifdef _DEBUG
QString FireBirdDatabase::qtIBasePluginName_ = "qsqlibased4.dll";
#else
QString FireBirdDatabase::qtIBasePluginName_ = "qsqlibase4.dll";
#endif

FireBirdDatabase::FireBirdDatabase()
    :isInitialized_(false), databasePath_(""), connectionName_(""), instances_(0), lastError_(0)
{
   
}

FireBirdDatabase::~FireBirdDatabase()
{
    

    Close();
}
bool FireBirdDatabase::Initialize()
{
    

    lastError_ = 0;

    if (isInitialized_)
    {
        return true;
    }

    if(!pluginLoader_.isLoaded())
    {
        pluginLoader_.setFileName(QApplication::instance()->applicationDirPath() + QDir::separator() + qtIBasePluginName_);
        
        if (!pluginLoader_.load())
        {            
            //// "Loading SQL Driver failed.";
            isInitialized_ = false;
            return false;
        }
    }

    QObject* object = pluginLoader_.instance();

    if (object == NULL)
    {            
        // "Loading SQL Driver Instance failed.";

        pluginLoader_.unload();
        return false;
    }

    QSqlDriverPlugin* plugin = qobject_cast<QSqlDriverPlugin*>(object);

    if (plugin == NULL)
    {            
        // "QSqlDriverPlugin == NULL");
        pluginLoader_.unload();
        return false;
    }

    driver_ = plugin->create("QIBASE");

    if (driver_ == NULL)
    {            
        // "Loading QIBASE Driver Instance failed.";
        pluginLoader_.unload();
        return false;
    }

    isInitialized_ = true;

    return isInitialized_;
}
bool FireBirdDatabase::Create(const QString& filePath, const QString& userName, const QString& password)
{

    if (!isInitialized_)
    {
        Initialize();
    }

    if (QFile::exists(filePath))
    {
        return false;
    }

    databasePath_ = filePath;

    QString queryString;
    queryString += "CREATE DATABASE";
    queryString += " \'" + filePath + "\'";
    queryString += " USER \'" + userName + "\'";
    queryString += " PASSWORD \'" + password + "\'";
    queryString += " DEFAULT CHARACTER SET UNICODE_FSS";

    ISC_STATUS_ARRAY status;
    isc_db_handle   databaseHandle = NULL;
    isc_tr_handle   transactionHandle = NULL;

    unsigned short g_nFbDialect = SQL_DIALECT_V6;

    if (isc_dsql_execute_immediate(status, &databaseHandle, &transactionHandle, 0, queryString.toStdString().c_str (), g_nFbDialect, NULL))
    {
        long SQLCODE=isc_sqlcode(status);
        return false;
    }



    isc_commit_transaction( status, &transactionHandle );

    if (databaseHandle != NULL)
    {
        ISC_STATUS_ARRAY status;
        isc_detach_database(status, &databaseHandle);
    }

    return true;
}
bool FireBirdDatabase::Open(const QString& filePath, const QString& userName, const QString& password)
{
    

    isInitialized_ = false;
    lastError_ = 0;

    if (!Initialize())
    {
        // "Firebird database is not initialized.";
        return false;
    }

    instances_++;

    connectionName_ = "Connection_1";
            
    QSqlDatabase database; 

    // "Adding database (DRIVER) ";
    database = QSqlDatabase::addDatabase(driver_, connectionName_);

    // "Check Valid database. ";
    if (!database.isValid())
    {
        QString lastError = database.lastError().text();
        // "Database is not valid. LastError = %S", lastError.toStdWString();
        return false;
    }

    // "Set database configurations.";

    database.setDatabaseName(filePath);
    database.setUserName(userName);
    database.setPassword(password);

    QString connectionString = QString(connectionString_).arg(filePath);
    database.setConnectOptions(connectionString);

    bool result = false;
    
    result = database.open();

    if(!result)
    {
        QString lastError = database.lastError().text();        
        lastError_ = (uint)database.lastError().number();        
    }
    return result;
}

bool FireBirdDatabase::Close()
{
    
    try
    {
        lastError_ = 0;

        QSqlDatabase database = QSqlDatabase::database(connectionName_);
        if (database.isValid() && database.isOpen())
        {
            database.close();
        }        
        QSqlDatabase::removeDatabase(connectionName_);
        driver_ = NULL;
    }
    catch (...)
    {
        return false;
    }

    return true;
}
bool FireBirdDatabase::IsOpen()
{
    

    QSqlDatabase database = QSqlDatabase::database(connectionName_);

    if (database.isValid() && database.isOpen())
    {
        return true;
    }

    return false;
}
QSqlQuery Model::FireBirdDatabase::CreateQuery()
{
    return QSqlQuery(QSqlDatabase::database(connectionName_));
}

int Model::FireBirdDatabase::LastError()
{
    return lastError_;
}