QSqlQuery different value() type

[Xardas]

Hi, have two tables(mysql)
first: id(unsigned int, primary_key, auto_increment), name(varchar(250)).
second: id(unsigned int, primary_key, auto_increment), name(varchar(250)), status(tinyint(1))...etc.
difference only in column count. But result of "SELECT id FROM..." :
first table: QVariant(uint, 1);
second table: QVariant(uchar, 1);

QSqlQuery query(*db);
query.prepare("SELECT test.test1.id FROM test.test1;");
if(query.exec())
{
   while(query.next())
   {
       qDebug() << query.value(0);
   }
}

before 5.6 have no problems
what could be the problem, any ideas?

[SGaist]

Hi,

What database driver are you using ?

Can you share the code you use to connect to the database ?

What version were you using before 5.6 ?

[Xardas]

Hi, previous version 5.5.1

main connection:

db = new QSqlDatabase();
*db = QSqlDatabase::addDatabase("QMYSQL");
db->setHostName("127.0.0.1");
db->setPort(3306);
db->setDatabaseName("testDB");
db->setUserName("root");
db->setPassword("1234567890");

if (db->open())
   doSomething();
else
   qDebug() << db->lastError();

inside taskThread:

void TaskThread::run()
{
   db = new QSqlDatabase();
   *db = QSqlDatabase::cloneDatabase(QSqlDatabase::database(),
    QString::number((qintptr)QThread::currentThread()));

   if (db->open())
      emit result(doSomething());
   else
      return;
}

QString TaskThread::doSomething()
{
   QSqlQuery query(*db);
   query.prepare("SELECT test.test1.id FROM test.test1"
   " WHERE test.test1.name=:name;");
   query.bindValue(":name", "name");

   if(query.exec() && query.first())
       return query.value(0).toString();
   else
       return 0;
}

driver - QMYSQL plugin from source
MySql server version 5.7.11

[Xardas]

Checked again, on 5_5_1 has no problem.
first table: QVariant(uint, 1);
second table: QVariant(uint, 1);

any ideas, what is the problem?

[SGaist]

One unrelated note, you're not using QSqlDatabase correctly. There's no need to use new on it.

What OS and MySQL version are you using ?

[Xardas]

OS: Windows 10
Mysql: 5.7.11

[SGaist]

Did you only change Qt version or also MySQL ?

Did you rebuild the MySQL plugin ?

[Xardas]

@SGaist said:

Did you only change Qt version or also MySQL ?

only Qt version

@SGaist said:

Did you rebuild the MySQL plugin ?

Yes

[SGaist]

What size are both tables ?

[Xardas]

first: 16KiB
second: 16KiB

[SGaist]

I meant number of rows of each tables.

[Xardas]

first table 129
second 3

[SGaist]

The plugin hasn't changed anything related to that between 5.5 and 5.6 so I wonder if it's a change in QVariant.

By the way, why do you need that information ? You should be able to just convert to int without any problem.