CREATE TABLE (
ADDR SMALLINT NOT NULL,
TAG SMALLINT NOT NULL,
VAL FLOAT,
DATE_TIME TIMESTAMP,
REQ_UPDATE INTEGER NOT NULL,
REAL_TIME INTEGER NOT NULL,
REQ_WRITE INTEGER NOT NULL,
CONSTRAINT UNQ_ADDR_TAG UNIQUE (ADDR,TAG)
)

SELECT TAG, VAL FROM RTTABLE 
    WHERE ADDR = 1 
              AND REAL_TIME = 1
              AND REQ_WRITE = 0

    if(!query->prepare(
        "SELECT TAG, VAL FROM RTTABLE "
             "WHERE ADDR = :id_addr "
                    "AND REAL_TIME = 1 "
                    "AND REQ_WRITE = 0 "
        )
    ){
        qDebug() << "IRTPoolTags::getPoolIncTags query->prepare"
                 << query->lastError();
        return;
    }

    query->bindValue(":id_addr",curAddr);

    if(!query->exec()){
        qDebug() << "IRTPoolTags::getPoolIncTags query->exec"
                 << query->lastError();
        return;
    }

    while(query->next()){
        PoolTag poolTag;
        poolTag.tag = query->value(0).toInt();
        poolTag.val = query->value(1).toDouble();

        listTag.append(poolTag);
    }

query = new QSqlQuery(db);

bool IncPool::openDB()
{
    db =  QSqlDatabase::addDatabase("QIBASE",threadID);

    db.setDatabaseName ("INCBASE") ;
    db.setUserName ("sysdba") ;
    db.setPassword("masterkey") ;

    db.setHostName ("localhost") ;

    if (!db.open()) {

        qDebug() << lastError;
        return false;
    }
    return true;
}

    threadID = QString::number(
                (qint32)QThread::currentThreadId(), 16).toUpper();

    if(!query->first()){
        return;
    }

    do{
        PoolTag poolTag;
        poolTag.tag = query->value(0).toInt();
        poolTag.val = query->value(1).toDouble();

        listTag.append(poolTag);
    }while(query->next());

//query.setForwardOnly(true);???

query.exec(QString(
                "SELECT TAG, VAL FROM RTTABLE "
             "WHERE ADDR = %1 "
                    "AND REAL_TIME = 1 "
                    "AND REQ_WRITE = 0 "
                .arg(curAddr)
                .toUtf8());

            if(query.isActive())
            {

		if(!query.isForwardOnly())
		{
			if(query.size() == 0)QDebug() << "query size = 0";
		}
		else

		if(query->first())
		{
			do
			{
				PoolTag poolTag;
        			poolTag.tag = query->value(0).toInt();
        			poolTag.val = query->value(1).toDouble();
        			listTag.append(poolTag);
			}
			while(query->next());
		}
		else QDebug() << "query size = 0"; 

while(query->next()){
…
}

QSqlQuery query(db);