QsqlDatabase: QMYSQL driver not loaded but available

davidesalvetti

Hi all,

I know this is a common problem, I tried to follow other posts but I can't solve the problem.
This is my simply code taken by QT:

#include <QSqlDatabase>
#include <QDebug>
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
   db.setHostName("bigblue");
   db.setDatabaseName("flightdb");
   db.setUserName("acarlson");
   bool ok = db.open();
   qDebug() << "OK? " << ok;
}

In the .pro

QT       += core gui sql

The error is:

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

I'm using QT 5.9.1 MinGW 32bit.

I tired to download the zip file for 32 bit from here and the to import the .dll from "mysql-connector-c++-8.0.16-win32/lib" to "C:\Qt\5.9.1\mingw53_32\bin" and also "C:\Qt\5.9.1\mingw53_32\lib" but nothing changed, still the same error. Can somebody give me an hint?

Christian Ehrlicher

Check e.g. with Dependency Walker if the mysql plugin (in plugins\sql) has all needed dependencies available.

arsinte_andrei

could be that you will need the ms lib dll and you are with minGW??

jsulm

@davidesalvetti Also, you can set QT_DEBUG_PLUGINS (https://doc.qt.io/qt-5/deployment-plugins.html) before starting your app and then expect its output.

KroMignon

@davidesalvetti I had a similar issue with MySQL plugin, as far as I known, Qt MySQL Plugin requires connector/c not connector/c++.
==> https://downloads.mysql.com/archives/c-c/
I had experience that it works with version 6.1.1 and older (version 6.1.2 and newer did not work on my PC)!

Download it from mysql, and put a copy in C:\Qt\5.9.1\mingw53_32\bin, this should work.... in fact it works for me ;)

davidesalvetti

@KroMignon wow, it works now! I was taking the wrong connector, thank you for the right link!