QHash<QThread *, Connection *>::iterator conIter;
for (conIter = _connectionPool.begin(); conIter != _connectionPool.end(); ++conIter) {
QSqlDatabase::removeDatabase(conIter.value()->name());
QHash<QThread *, Connection *>::iterator conIter;
for (conIter = _connectionPool.begin(); conIter != _connectionPool.end(); ++conIter) {
QSqlDatabase::removeDatabase(conIter.value()->name());