QSqlDatabase: QODBC driver not loaded - problem

[Arturs]

Hi

I have the following code :

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <QSqlDatabase>
#include <QSqlQuery>
 
 
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::on_pushButton_clicked()
{
 
    QSqlDatabase db = QSqlDatabase::addDatabase("QODBC");
    db.setDatabaseName("Driver={Microsoft dBASE Driver (*.dbf)};DriverID=277;Dbq=d:/TEST");
    db.open();
}

after pressing button I see the messages "

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

How to solve the problem ?
How to load the driver.

I use Windows 7 64bit.

Regards
Artur

[VRonin]

It's a "feature" of Qt 5.6, see https://bugreports.qt.io/browse/QTBUG-49420 for report and solution

[Arturs]

Thank you for information. Now Everything is clear and know why I spent so many hours and still problem with ODBC.

ODBC Build Steps

cd c:/Qt/Qt5.6.0/5.6/Src/qtbase/src/plugins/sqldrivers/odbc
qmake odbc.pro
nmake
nmake release
nmake install
nmake release-install

I am quite new in QT so I do not know how to do above procedure. Where can I download odbc.pro ?

[beecksche]

Hi @Arturs,
you need to download the source files of Qt 5.6 and then take a look here http://doc.qt.io/qt-5.6/sql-driver.html#qodbc-for-open-database-connectivity-odbc, section How to Build the ODBC Plugin on Windows. It says:

The ODBC header and include files should already be installed in the right directories. You just have to build the plugin as follows:

cd %QTDIR%\qtbase\src\plugins\sqldrivers\odbc
qmake odbc.pro
nmake

If you are not using a Microsoft compiler, replace nmake with make in the line above.

Hope this helps

[Arturs]

you helps a lot.

I did everything as described above.

What files should be result of ? What to do next ?

[beecksche]

@Arturs
The lines above should create your necessary libraries (dlls / libs).
I have done this a long time ago, so i do not remeber where the files are created, sorry for that.

Update:
I am not quite sure but take a look at this directory:

%QTDIR%\qtbase\plugins\sqldrivers

[Arturs]

I am not sure that I install plugin in proper way.

In readme file is the following information:

"You will need ODBC development headers and libraries installed before
compiling this plugin."

Where to find headers and libriaries ?

What I did:

• downloaded qt sources
• open odbc catalogue - cd %QTDIR%\qtbase\src\plugins\sqldrivers\odbc in command prompt
• used the command - qmake odbc.pro

before using the command in the catalogue were only the files:

main.cpp
odbc.json
odbc.pro

after compiling are more files but there are not any dll files

[beecksche]

I have updated my post:

@beecksche said:

@Arturs
...
Update:
I am not quite sure but take a look at this directory:

%QTDIR%\qtbase\plugins\sqldrivers

[Arturs]

screen of catalogue D:\qt-everywhere-opensource-src-5.6.0\qt-everywhere-opensource-src-5.6.0\qtbase\src\plugins\sqldrivers after compilation

.moc
.obj
.pch

are empty.

[hskoglund]

Hi, there's an alternative solution: if you update to Qt 5.6.1 the QODBC driver plugin is included again (just like it was before Qt 5.6).

[beecksche]

@Arturs

You are in the wrong directory. I think in your case it should be:

D:\qt-everywhere-opensource-src-5.6.0\qt-everywhere-opensource-src-5.6.0\qtbase\plugins\sqldrivers

or download the new Qt 5.6.1 (released on 8th of June 2016), like @hskoglund said.

[Arturs]

I installed new version of Qt 5.6.1 for Windows 64-bit (VS 2015, 836 MB) (info) but now during compilation I have the following error:
"Error while building/deploying project Gunsbase (kit: Desktop Qt 5.6.1 MSVC2015 64bit) When executing step "Make"