Like a session in PHP

[wirasto]

I'm so impressed with QSqlDatabase. If I set like this..

QSqlDatabase db=QSqlDatabase::addDatabase(...);
db.setHostName("abc");

QSqlDatabase db=QSqlDatabase::addDatabase(...);
db.setHostName("abc");

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Then, I can get value "abc" in everywhere with

qDebug() << QSqlDatabase::database().hostName()

qDebug() << QSqlDatabase::database().hostName()

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I think that is like set $_SESSION["hostName"]="abc" in PHP.
How to create like that with Qt ?

[Lykurg]

Please, do not post multiple the same issue, and this one I haven't understand... Just because of your former post...

Look for a Singleton pattern.

[wirasto]

Okh

I can get my variable value in every where with that ?

I want have a function like $_SESSION[..] in PHP. So if I need the variable value in other dialog, i not need pass the variable to other dialog any more.

Sorry, with my english..

[Lykurg]

I can get my variable value in every where with that ?

Have you take a look at it? Yes you can, that's the reason I post it

int abc = Singleton::instance()->getMyFancyVariable();

int abc = Singleton::instance()->getMyFancyVariable();

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[wysota]

Just to make it clear - $_SESSION is not global anymore in php so you can't access it from anywhere in your script unless you register it as global. And if you do, it's direct equivalent in C++ is a global variable as well.

QHash<QString,QVariant> _SESSION; // in cpp somewhere
//...
extern QHash<QString,QVariant> _SESSION; // in .h
// ...
 
_SESSION["x"] = "y";

QHash<QString,QVariant> _SESSION; // in cpp somewhere
//...
extern QHash<QString,QVariant> _SESSION; // in .h
// ...

_SESSION["x"] = "y";

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Of course it's much better to use a singleton as suggested, both in C++ and PHP.