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.