Problem with QMYSQL

[AlexW.QT]

Hi. I know that there's a lot of topics about it, but this is uncommon.
Problem is that qmysql.dll loads ONLY from mingw folder and nothing helps. fighting with this 2 days and cant resolve it.
pls help

here's some code (setting up libs load from exe folder):
QStringList str;
str.append(".");
qApp->setLibraryPaths(str);

in PRO:
QTPLUGIN += QSQLMYSQL
QT += sql core gui

[SGaist]

Hi and welcome to devnet,

If you want the plugin to load when deploying your application, you have to respect the folder hierarchy. So you have to keep plugins/sqldrivers beside your application.

[AlexW.QT]

It is. All the folders near exe. All dlls in there.
Used windeployqt for it. All ok if only mingw folder exists, if not - won't load and not workin'

[SGaist]

Did you also deploy MinGW's dlls ?

One thing you can do is start your application from the command line with the QT_DEBUG_PLUGINS environnement variable set to 1.

You'll what is happening when your plugins are getting loaded.

[AlexW.QT]

@sgaist all in there (every folder have from 1 up to 9 dlls)

And this is sqldrivers folder

Problem is that if C:\Qt\5.11.3\mingw53_32\plugins\qsqlmysql.dll exists, all ok. If I remove it - it doesn't loads from exe folder and C:\Deploy\libmysql.dll not loading too.

[AlexW.QT]

FOUND WHERE'S PROBLEM

But still need help.

Problem is that driver loading before setting up default folder:

QStringList str;
str.append("C:\Deploy");
qApp->setLibraryPaths(str);

And getting this err:

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QODBC QODBC3 QPSQL QPSQL7
QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins
my library path : ("C:\Deploy")

Problem in database.cpp:

#include "database.h"
static QSqlDatabase datb = QSqlDatabase::addDatabase("QMYSQL", "datas");
static QSqlQuery query(datb);

static QString host = "site.host";
static QString namedb = "name";
static QString nameusr = "usr";
static QString passdb = "pass";
//db login & open
void Database::login_db()
{
}

Exact problem in:
static QSqlDatabase datb = QSqlDatabase::addDatabase("QMYSQL", "datas");

This line loading before int main(int argc, char *argv[]) and upload's qmysql from default folder of mingw

If I remove it from there and put into login func all with loading is ok:

But doesn't work then my functions. How can I solve it? how to move these lines in another place:

static QSqlDatabase datb= QSqlDatabase::addDatabase("QMYSQL", "datab");
static QSqlQuery query(datb);

I mean load 'em later than main.cpp

[AlexW.QT]

OR make default DIR outside of main OR in .PRO file.

[SGaist]

Are you trying to move things around in the folder where you are currently doing the application deployment ?