database problem

[rogerholmes]

I do not have the mySql driver so i am trying to connect to mySql using odbc. It seems to connect and open but i can not query the database. can someone please help me out?

{
    QSqlDatabase Db = QSqlDatabase::addDatabase("QODBC", "Calendar");
 
    Db.setHostName("localhost");
    Db.setDatabaseName("mySql");
    Db.setUserName("root");
 
   bool goodQuery;
   bool validrec;
int x;
x=1;
 
if(Db.open())    // database is open
   {
    QSqlQuery query(Db);
    query.exec("SELECT * from artist" );
    goodQuery=query.isActive();          // this returns true
    query.first();
    validrec=query.isValid();   // this returns false
    x=query.size();    // this returns -1
 
    while(query.next()){
     new QListWidgetItem(tr("Hazel"), ui->listWidget);  //this never executes
      }
   }
Db.close();
}

{
    QSqlDatabase Db = QSqlDatabase::addDatabase("QODBC", "Calendar");

    Db.setHostName("localhost");
    Db.setDatabaseName("mySql");
    Db.setUserName("root");

   bool goodQuery;
   bool validrec;
int x;
x=1;

if(Db.open())    // database is open
   {
    QSqlQuery query(Db);
    query.exec("SELECT * from artist" );
    goodQuery=query.isActive();          // this returns true
    query.first();
    validrec=query.isValid();   // this returns false
    x=query.size();    // this returns -1

    while(query.next()){
     new QListWidgetItem(tr("Hazel"), ui->listWidget);  //this never executes
      }
   }
Db.close();
}

To copy to clipboard, switch view to plain text mode 

[rogerholmes]

i have further tracked this down

query.lasterror() returns :
QSqlError(0, "QODBC3: Unable to fetch first", " [iODBC][Driver Manager]Optional feature not implemented")

what does this mean?

[ChrisW67]

The query cursor is probably opened in a forward-only mode and cannot 'reverse' to the first record (or the ODBC driver does not support doing this). Comment out line 18 and see how you get on.

[rogerholmes]

thank you for your response, i did as you suggested :

now the error is :QSqlError(-1, "", "") , looks like progress