Error compiling libqsqlmysql.so ( On Ubuntu)

[CristianoNarcisiVidex]

Hi all
i am writing a stupid thread that needs to read some settings from a mysql database. Here i have snippet of code:

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


    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    db.setDatabaseName("mydb");
    db.setUserName("root");
    db.setPassword("root");
    db.setHostName("localhost:50000");

    if(db.open())
    {
        qDebug() << "ok";
    }
    else
    {
        qDebug() << "ko";
    }
    return a.exec();
}

This code prints "ko". The very strange thing is that replacing QMYSQL with QSQLITE the database connection is correctly opened! I was wondering if the problem is on the connector. I have made ldd on libqsqlmysql.so and this is the output:

~/Qt_5.12/5.12.2/gcc_64/plugins/sqldrivers$ ldd libqsqlmysql.so

linux-vdso.so.1 =>  (0x00007fffc5fdc000)
	libQt5Sql.so.5 => /home/cristiano/Qt_5.12/5.12.2/gcc_64/plugins/sqldrivers/./../../lib/libQt5Sql.so.5 (0x00007fe96e0c5000)
	libQt5Core.so.5 => /home/cristiano/Qt_5.12/5.12.2/gcc_64/plugins/sqldrivers/./../../lib/libQt5Core.so.5 (0x00007fe96d932000)
	libmysqlclient.so.20 => /usr/lib/x86_64-linux-gnu/libmysqlclient.so.20 (0x00007fe96d2e8000)
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fe96cf65000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe96cb9b000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fe96c97e000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fe96c674000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fe96c45e000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fe96c244000)
	libicui18n.so.56 => /home/cristiano/Qt_5.12/5.12.2/gcc_64/plugins/sqldrivers/./../../lib/libicui18n.so.56 (0x00007fe96bdaa000)
	libicuuc.so.56 => /home/cristiano/Qt_5.12/5.12.2/gcc_64/plugins/sqldrivers/./../../lib/libicuuc.so.56 (0x00007fe96b9f2000)
	libicudata.so.56 => /home/cristiano/Qt_5.12/5.12.2/gcc_64/plugins/sqldrivers/./../../lib/libicudata.so.56 (0x00007fe96a00f000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fe969e0a000)
	libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fe969c08000)
	libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fe9698f7000)
	/lib64/ld-linux-x86-64.so.2 (0x000055668565a000)
	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fe969686000)

As you can see, all the dependencies are respected.

What am i doing wrong?
i think that i am making a very stupid error.

Sorry for wasting you all time.

Thanks

Cristiano

[jsulm]

@CristianoNarcisiVidex What does https://doc.qt.io/qt-5/qsqldatabase.html#lastError say (after open())?

[JonB]

@CristianoNarcisiVidex

db.setHostName("localhost:50000");
The very strange thing is that replacing QMYSQL with QSQLITE the database connection is correctly opened!

So you have both QMYSQL and QSQLITE listening on the same port number?? Or, you have QSQLITE listening there, hence it's wrong for QMYSQL?

[CristianoNarcisiVidex]

Re: Error compiling libqsqlmusql.so ( On Ubuntu)

Hi All

As i have predicted before, there was a very stupid error! It seems that

 db.setHostName("localhost:50000");

is not valid using QMYSQL, but is valid for QSQLITE

i have replaced it with

db.setPort(50000);
 db.setHostName("localhost");

And now i can connect to the db using the QMYSQL connector

Sorry for bothering you!

Thanks

Cristiano