[Qt-interest] Design of Qt/DB applications

[William Lugg]

OK, here's what may be a duh question.

I've been trying to study the SQL examples and figure that out, but have 
failed.  I'm working on an application that will provide a rather elaborate 
membership roster for an organization.  It is using SQLite for the DB engine 
and Qt  (obviously) for the GUI.  I've build a simple class to handle the 
connection of the app to the DB and got the impression from the examples that 
I should place a call to the static connection::createConnection() in main.cpp 
before I started the app itself.  However, after some debugging, I'm 
discovering that it looks like I need the createConnection call in each form 
and dialog I open that needs access to the DB.  Is the correct or am I not 
doing the right things in my createConnection code?  Here's the code if that 
helps...

bool Connection::createConnection()
{
   QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE", "rlhs_db");

   db.setDatabaseName("../database/rlhs_db");
   if (db.open())
   {
      return true;
   }
   else
   {
      QMessageBox::critical(0,
                            qApp->tr( "Cannot open database"),
          qApp->tr( "Unable to establish a database connection.\n"
                   "This application needs SQLite support. Please read "
                   "the Qt SQL driver documentation for information how "
                   "to build it.\n\n"
                   "Click Cancel to exit."),
                            QMessageBox::Cancel);

      return false;
   }
}

Looks a lot like the example code, doesn't it?  :o)

Thanks for the help.
----
Bill Lugg
  Milstar Software Support
  Peterson AFB, CO
  No Micro$oft products were used to create this email.  
  God rules and if He needed a computer it would run Linux!


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