Sqlite3 window problem

[giusepped]

There are differences between QSQLITE in windows and in linux?
In linux, if the database doesnot exist Qt create a new file with the databasename.
In windows it does not, although I can use the database.
Perhaps, the sqlite database has been creating in memory, or what?
G

[spirit]

on windows Qt also creates file with databasename in app directory.
but if you this like this

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName(":memory:");

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName(":memory:");

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then the database will be allocated in memory.

[giusepped]

I did not.

QSqlDatabase d =  QSqlDatabase::database();
        d.setDatabaseName(databaseName);

QSqlDatabase d =  QSqlDatabase::database();
        d.setDatabaseName(databaseName);

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Still, I cannot see the file in the any folder, but I can do sql query!
How is it possible?
even if I close the application the database file is not present....

[spirit]

did you change work directory (dest dir) in pro-file?

[giusepped]

I don't know what you are talking about....
Please, shine me!

[spirit]

ok, build an troll's example. go to QTDIR/examples/sql and in connection.h change the next lines

//    db.setDatabaseName(":memory:");
    db.setDatabaseName("test.db");

//    db.setDatabaseName(":memory:");
    db.setDatabaseName("test.db");

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then go (for example) to cachedtable dir, build and run this example. the "test.db" file should be with executable file.

[giusepped]

I still do not understand.
My exec is in debug folder.
If I try to create a database e.g. d.setDatabaseName("pinco.db"), the database FILE is correctly created in the debug folder.
BUT: If i try to create d.setDatabaseName("C:/Docuemnts and Settings/giuse") the file IS NOT CREATED, but I can make queries!
G

[spirit]

I've tried to connect to a database with name wich you specified and a file was created.

[giusepped]

You are under windows?
The same code under linux works (the file is created). But in windows not.
I am desperate.
Anyway, a solution is to close the connection, reopen it with addDatabase.
In this case the file is created.
G

[spirit]

I'm under windos now and a file creates fine. which version of Qt do you use? maybe this is a bug. I use 4.3.5.

[giusepped]

I did not want to post the code, but I am really confused.
Actually, the error is present in linux too.
In my mainwindow constructor I did

mainWindow::manWindow(
....
db = QSqlDatabase::addDatabase("QSQLITE");
        if (createConnection())
        {	
		initializeModel();
		createView();
		updateDetails(QModelIndex());
....
        }
}

mainWindow::manWindow(
....
db = QSqlDatabase::addDatabase("QSQLITE");
        if (createConnection())
        {	
		initializeModel();
		createView();
		updateDetails(QModelIndex());
....
        }
}

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and

bool mainWindow::createConnection()
{
 
 
        /* If the database do not exist
        I create one anew*/
 
        QFile check;
        check.setFileName(databaseName);
        QDir::setCurrent(QCoreApplication::applicationDirPath());
       db.setDatabaseName(databaseName);
 
	if (!check.exists()){
 
                #ifdef DEBUG
                qDebug()<<databaseName<<"do not exist. However, is open="<<db.open();
                #endif
                currentDatabase =  databaseName ;
	createTable();
	statusLabel->setText(currentDatabase);
        }
        if (!db.open()) {
 
        #ifdef DEBUG
        qDebug()<<db.lastError()<<db.open();
        #endif
         removeConnection();
         return false;
        }

bool mainWindow::createConnection()
{

 
        /* If the database do not exist
        I create one anew*/

        QFile check;
        check.setFileName(databaseName);
        QDir::setCurrent(QCoreApplication::applicationDirPath());
       db.setDatabaseName(databaseName);
        
	if (!check.exists()){
                 
                #ifdef DEBUG
                qDebug()<<databaseName<<"do not exist. However, is open="<<db.open();
                #endif
                currentDatabase =  databaseName ;
	createTable();
	statusLabel->setText(currentDatabase);
        }
        if (!db.open()) {
                
        #ifdef DEBUG
        qDebug()<<db.lastError()<<db.open();
        #endif
         removeConnection();
         return false;
        }

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When I wanna add a new datatabase (which in SQLITE means a new file!) I do

void mainWindow::newDB()
{
        /* Create a new archive*/
 
        QString fileName = QFileDialog::getSaveFileName(this, tr("Nuovo archivio"),QDir::homePath (),tr("Rubic database (*.db)"));
        QFile f(fileName);
 
 
        if (fileName != currentDatabase)
        {
	db.setDatabaseName(fileName);
	#ifdef DEBUG
	qDebug()<<"newDB, opening"<<db.lastError()<<"is open="<<db.isOpen()<<fileName<<db.isValid();
	#endif
	if (db.isValid()){
			currentDatabase = fileName;
			createTable();
			initializeModel();
	 		createView();
			updateDetails(QModelIndex());
			statusLabel->setText(currentDatabase);
}
	}
}
 
                currentDatabase = databaseName;
                return true;
 
}

void mainWindow::newDB()
{
        /* Create a new archive*/

        QString fileName = QFileDialog::getSaveFileName(this, tr("Nuovo archivio"),QDir::homePath (),tr("Rubic database (*.db)"));
        QFile f(fileName);


        if (fileName != currentDatabase)
        {
	db.setDatabaseName(fileName);
	#ifdef DEBUG
	qDebug()<<"newDB, opening"<<db.lastError()<<"is open="<<db.isOpen()<<fileName<<db.isValid();
	#endif
	if (db.isValid()){
			currentDatabase = fileName;
			createTable();
			initializeModel();
	 		createView();
			updateDetails(QModelIndex());
			statusLabel->setText(currentDatabase);
}
	}
}
 
                currentDatabase = databaseName;
                return true;

}

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The funny think is
1) After the start up, If I create a newDB, the debug messages say that the database has been created. IN fact I can use the queries but I cannot see any database file in the choosen dir
2) If I quit the application, since a write the currentDatabase var. inside a QSettings, the debu message says that the database does not exist and it will create it.
3) The only way I found to let it work is to addDatabase also in the newDB function.

Any suggestion appreciated

[giusepped]

I found a solution but I do not understand why it is working.
First I create a static member function in mainWindow:

bool mainWindow::createConnStatic()
{
	QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
 
}

bool mainWindow::createConnStatic()
{
	QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");

}

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which is declared static in the header file.

Now, at the startup I create a connection by calling this function. db is a member variable.
When I wann change database, I do

QSqlDatabase db =  QSqlDatabase::database();
db.setDatabaseName(s);

QSqlDatabase db =  QSqlDatabase::database();
db.setDatabaseName(s);

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This work pretty well, but is "impossible" to got there by reading the Qt Doc.