Win 10 drivers mysql not load

[SGaist]

Hi,

Is your MySQL .dll built for MinGW ?

On a side note, don't install .dlls like that in C:/Windows/System32. That's bad habit and can wreak havoc on other application that might load that version rather that the one they are supposed to use.

[TheCipo76]

ok, i don't put lib in C:\windows\System32
thanks for information..

about mysql c++ connector building
i've read that is compatible only with Visual Studio in Windows..

i've try for 3 hours .. (later that i had search in google...)
using MySQL Server 5.7
cmake 3.13
make 3.81 (GnuWin32)
MinGW 32 6.3.0-1

cmake is ok but make give me some error..

driver/CMakeFiles/mysqlcppconn.dir/mysql_art_resultset.cpp.obj
driver/CMakeFiles/mysqlcppconn.dir/all

i don't know how to solve this problem..

[SGaist]

I don't either because you didn't post the actual error.

[TheCipo76]

After download MySQL community 5.5.61 Win32
i've tried following:

1. Qt Documentation (http://doc.qt.io/qt-5/sql-driver.html#building-the-drivers)
2. this tutorial (https://www.seppemagiels.com/blog/create-mysql-driver-qt5-windows)

but can't compile MySQL drivers..

in the first case (1) i have no opt folder then i had this result (MySQL .... no)

in the second one (2) this:

any ideas??

If it's possible i will use 64 bit however..

[SGaist]

What parameters did you pass to configure ?
You can use the -v option to get more information about what is failing.

If you currently want to use 64bit MySQL, then you'll have to switch over to Visual Studio or build Qt yourself in 64 bit for MinGW.

[TheCipo76]

i will use 32 bit ..

i've built my project (from QT Creator) and then used windeployqt to create a standalone windows app..

app was loaded well.. but i still have the "Driver not loaded" problem (MySQL)
(both my dev machine with Qt dir renamed, and in an other machine with windows 10).

how can i solve it??

[SGaist]

Did you check that you have the MySQL dll also deployed ?

[TheCipo76]

@SGaist no dll (because is 3rd part??)
i've tried to copy the dll in the folder of exe file but don't work!

now i removed mysql and re-download and extract it.
i've followed the qt documentation (http://doc.qt.io/qt-5/sql-driver.html#qmysql)
but i've this problem:

1. cd %QTDIR%\qtbase\src\plugins\sqldrivers
   impossible to find specified path

   i went manually to the path
   C:\Qt\5.11.2\Src\qtbase\src\plugins\sqldrivers

2. run:
   qmake -- MYSQL_INDIR=C:/PROGRA~2/MySQL/MYSQLS~1.5/include "MYSQL_LIBDIR=C:\PROGRA~2\MySQL\MYSQLS~1.5\lib"

3. mingw-make sub-mysql
   give me this result:
   mingw32-make: *** No rule to make target 'sub-mysql'. Stop

I think that is difficulto to build this plugin.. i've already tried many times but i can't go out of gallery!!

i've searched mysql file, found in:

mysql.h ---> C:\Program Files (x86)\MySQL\MySQL Server 5.5\include
mysql.lib ---> C:\Program Files (x86)\MySQL\MySQL Server 5.5\lib

Any help??

[SGaist]

Something's not clear, didn't you have that running properly before deployment ?

[TheCipo76]

@SGaist yes it'ok run very well

i've built it with Qt Creator
then i have used windeployqt
all it's ok
but when i try to rename Qt folder don't work
and show the message i've post

can i do any check to verify which is the problem?

[SGaist]

If your application runs properly when using Qt Creator, it's likely that you are missing the MySQL .dll (as in the dependencies of the plugin).

Use Dependency Walker to check that.

[TheCipo76]

i'm trying with this :

https://wiki.qt.io/Deploy_an_Application_on_Windows

i've copy files and folders from

mingw../bin (all dll files)
mingw../plugins (all folders)

to my app folder

i've renamed "Qt" in "xxxQt" (to hide Qt folder)

lauched my app (works) and delete all dll (some dll was not deleted..)

i have deleted all dll files folder by folder

it isn't the correct way i think but seem it works now..

[rch_shukla]

hello
I have completed mysql driver loading. it loaded successfully but new problem arises ,mysql plugin is failed with qt.I have tried all the solution provided on google yet not succeeded.
Any idea what am i missing here.
I am using qt 5.10.1,windows 10,mysql 32 bit.
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QSqlRecord>
#include<QSqlDriver>
#include <QSqlDatabase>
#include <qsqldatabase.h>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL","test1");
qDebug()<<"running1";

QStringList liblist;
liblist.push_back("C:/Qt/5.10.1/Src/qtbase/src/plugins/sqldrivers");
liblist.push_back("C:/Qt/5.10.1/Src/qtbase/src/plugins");
QCoreApplication::setLibraryPaths(liblist);

QLibrary mysqllib("libmysql.dll");
mysqllib.load();
auto t1 = mysqllib.isLoaded();
qDebug()<<"my library loaded"<<mysqllib.isLoaded();

/////it is working fine till here
QPluginLoader plug("qsqlmysqld.dll");
plug.load();
auto t = plug.isLoaded();
//this is failed
qDebug()<<"plugin is loaded"<<plug.isLoaded();

  db.setHostName("127.0.0.1");
  db.setUserName("root");
  db.setPassword("Stampsoft2018");
  db.setDatabaseName("test1");
  db.setPort(3306);
  qDebug()<<"running2";

// qDebug()<<db.open();
// if(!db.open())
// {
// qDebug()<< "Database error Occurred";
// return false;
// }

// qDebug()<<QSqlDatabase::drivers();
if (db.open())
{
qDebug()<<"DB is opened";
QSqlQuery myquery;
qDebug()<<"till here..";
if (myquery.exec("SELECT name, age, gender FROM employee"))
{
while (myquery.next())
{
qDebug() << myquery.value(0) << myquery.value(1) << myquery.value(2);

        ui->name->setText(myquery.value(0).toString());
        ui->age->setText(myquery.value(1).toString());
        ui->gender->setCurrentIndex(myquery.value(2).toInt());

      }
    }
    else
    {
      qDebug() << myquery.lastError().text();
    }

    db.close();
  }
  else
  {
    qDebug() << "Failed to connect to database.";
  }

}

MainWindow::~MainWindow()
{
delete ui;
}
output-
running1
my library loaded true
plugin is loaded false
running2
Failed to connect to database.

[SGaist]

Hi and welcome to devnet,

Did you print the actual error from the QSqlDatabase object ?
Did you run your application with the QT_DEBUG_PLUGINS environment variable set to one ?