public boolean contains(String guid) {
if (wordList.size() == 0)
return true;
QSqlQuery query = new QSqlQuery(db);
query.prepare("select count(guid) from guidList where guid=:guid");
query.bindValue("guid", guid);
query.exec();
while (query.next()) {
Integer count = new Integer(query.value(0).toString());
if (count >= wordList.size()) {
query.clear();