QSqlQuery causing ODBC Function sequence error

pdsc_dy

I searched this forum, SO, and Google but didn't find much help on this question. It seems due to ODBC functions being called out out of order. But since I am using QSql that wraps ODBC, it is hard for me to track down the function. Please help...

I was able to connect to the sql server database
I tested a very simply query and still got the error. I don't think it's due to column binding.
I was able to run the query with sql server, so I think the sql query is ok.

The tools I am using:
VS c++ 2017, CMake, Qt 5.09.2, sql server 2017
Below are the error messages:

QODBCResult::exec: Unable to execute statement: "[Microsoft][ODBC Driver Manager] Function sequence error" QSqlError("0", "QODBC3: Unable to execute statement", "[Microsoft][ODBC Driver Manager] Function sequence error")

Test coding:
This coding generate the error message above.

int main()
{
    QSqlDatabase GUIInpDB = QSqlDatabase::addDatabase("QODBC", "MainSQLDB");
    GUIInpDB.setConnectOptions();
    QString inpSqlServer = "DESKTOP-085AEA8\\SQLEXPRESS";
    QString dbName = "test";
    QString connString = QString("Driver={ODBC Driver 13 for SQL Server};Server=%1;DATABASE=%2;Trusted_Connection=Yes;")
        .arg(inpSqlServer).arg(dbName); //the argument replace the %1 and %2
    GUIInpDB.setDatabaseName(connString);
    QSqlDatabase db = QSqlDatabase::database("MainSQLDB");

    if (!db.open())
    {
        qDebug() << "Connection for db not working";
        return 1;
    }
    QSqlQuery query("SELECT * FROM TBL.tbl_test", db);  
    if (!query.exec())
        qDebug() << query.lastError();

    int num_of_rows = query.size();

    getchar();
    return 0;
}

Christian Ehrlicher

Hi, this looks like https://bugreports.qt.io/browse/QTBUG-54880 - can you please elaborate?

btw: The ODBC driver does not support QSqlQuery::size() - see http://doc.qt.io/qt-5/qsqldriver.html#DriverFeature-enum

pdsc_dy

@Christian-Ehrlicher Thanks for your quick response. Yes I also noticed the bug report, and tried to apply the query using QSqlQuery::exec(), but still got the same problem. I also tried adding "QCoreApplication::processEvents();" before QSqlQuery. That does not solve the problem either. I have tried everything I can. It does look like a bug but I don't have enough experience to tell whether it's a bug. Can you please help me. Thanks!

JonB

@pdsc_dy
That bug report is against SQL 2005, which is a lot older than 2017. Just saying.

So they want you to try:

    QSqlQuery query(db);  
    if (!query.exec("SELECT * FROM TBL.tbl_test") ...

?

Also what's your TBL referring to?

pdsc_dy

@JonB I think the user asking the question tried the QSqlQuery query(db) and it worked for him, but not for me.

TBL is a schema I created in the sql database, using the following coding. Do you think this would cause issues?

CREATE SCHEMA TBL AUTHORIZATION dbo;

hskoglund

Hi, if you're having doubts about your own created database, you could try using Qt for opening one of Microsoft's demo databases, for example the Northwind database