ODBC function sequence error

[joseph]

Hi guys

My Code is something like this




static bool DBConnection ::createODBC_Connection()
{
m_db = QSqlDatabase::addDatabase("QODBC");

m_db.setDatabaseName( "Test_DataSourceName" ); //DSN created in ControlPanel=> Administrative Tools ODBC Connection => System DSN =>..ADD

m_db.setConnectOptions ("SQL_ATTR_ODBC_VERSION=SQL_OV_ODBC3");
if (! m_db.open())
{
return false;
}
return true;
}


Now am using this code in main.cpp like this



int main(int argc, char *argv[])
{
QApplication a(argc, argv);

if( ! DBConnection::createODBC_Connection() )
{
QMessageBox::information( 0 ,"" , DBConnection::getDBErrorInfo() );
return 1;
}

MainWindow w;
w.show();
return a.exec();
}





For testing this code i have created class MainWindow and put the code like this
in the constructor itself


#include <QSqlQuery>
#include <QMessageBox>
#include <QSqlError>

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent), ui(new Ui::MainWindowClass)
{
ui->setupUi(this);
//TEST_BEGIN
QSqlQuery query("SELECT name FROM employee where emp_id = 7");
if( query.exec() )
{
if( query.next() ) //while (query.next())
{
QString empName = query.value(0).toString();
this->setToolTip( empName );
//QMessageBox::information( this ,"" ,empName );
}
}
else
{
QMessageBox::information( this ," In Mainwindow::Mainwindow()" ,
query.lastError().databaseText() +"\n" // Here i am getting ODBC //error "Function sequence error"
// statement cann't be executed

+ query.lastError().driverText() +"\n"
+ query.lastError().text() );
}
//TEST_END

}


When i am running my application i am getting following error ...
[ODBC Driver Manager] "Function sequence error"
[ODBC Driver Manager] can not execute statement
[ODBC Driver Manager] "Function sequence error" QODBC3 : unable to execute statement


MY Operating System = Windows XP
IDE = QtCreator Beta ( comes with qt library )
Database = Mysql
ODBC Driver = Mysql ODBC 3.51 Driver ( i can see it in Control panel )

Please correct me if am doing something wrong.

thanks in advance

[joseph]

Please help me with some tips to solve this ODBC error ....i got stuck with this issue.. :(

[^NyAw^]

Hi,

Can you insert debug points and take a look on wich instructions get you this errors?
Maybe then we can think on where is the problem.

[joseph]

Hi,

Can you insert debug points and take a look on wich instructions get you this errors?
Maybe then we can think on where is the problem.


Thanks for your kind reponse.

Actually i am getting this error in query.exec() as specified below...


if( query.exec() )
{
if( query.next() ) //while (query.next())
{
QString empName = query.value(0).toString();
this->setToolTip( empName );
//QMessageBox::information( this ,"" ,empName );
}
}
else // Control comes here inside this else block and i am able to see the query.lastError() ===> " [ODBC DRIVER] Function sequence error "
{
QMessageBox::information( this ," In Mainwindow::Mainwindow()" ,
query.lastError().databaseText() +"\n"
+ query.lastError().driverText() +"\n"
+ query.lastError().text() );
}



please tell me how can i resolve this ...:confused:

[^NyAw^]

Hi,

Maybe ODBC driver is case sensitive? I'm just thinking what is the problem, don't relly know what produces it.
Try changing "where" to "WHERE" in your query.

Also try removing this line:


m_db.setConnectOptions ("SQL_ATTR_ODBC_VERSION=SQL_OV_ODBC3");


I can't find "SQL_ATTR_ODBC_VERSION" on "setConnectionOptions" doc.

[joseph]

can someone help me ....:(
am i doing something wrong in my code ( in above mention code snippt )...?:confused:

[spirit]

try to connect to your database using Qt's example located on QTDIR/demos/sqlbrowser.

[mwaqqas]

can someone help me ....:(
am i doing something wrong in my code ( in above mention code snippt )...?:confused:

I struggled with this for a bit and found out how to fix it. Change your code to:

QSqlQuery query(QSqlDatabase::database());
if( query.exec("SELECT name FROM employee where emp_id = 7") )

It works, don't ask me why.

[Viper666]

Have you got 64 bit windows?

[emobemo]

The documentation for the QSqlQuery constructor says "If query is not an empty string, it will be executed.", which means that when you call exec() you are executing it twice.