QPSL driver is not loaded Win10 MSVC 2015 x64

koronabora

Hello! I need some help with the most popular question at this section: QPSQL driver is not loaded error.

OS: Windows 10 x64
MSVC 2015 x64
PostgreSQL: 9.5.2 x64
Qt sql driver: from official installer msvc2015_x64

Dependencies of all libraries checked:
qt plugin:
https://yadi.sk/i/J8ybogz1qsamK
warngings:
https://yadi.sk/i/W8giYWPiqsapa
psql:
https://yadi.sk/i/PON_W6YrqsawK
warngings:
https://yadi.sk/i/vx_fjPM-qsazs

Some code:

bool SQLContorller::_init()
{
	_sqlBase = new QSqlDatabase();
	_sqlBase->addDatabase(_SQL_DRIVER); //"QPSQL"
	_sqlBase->setHostName(_host);
	_sqlBase->setPort(_port);
	_sqlBase->setDatabaseName(_baseName);
	_sqlBase->setUserName(_name);
	_sqlBase->setPassword(_pass);
	return _sqlBase->open();
}

Debug information from QT:

QFactoryLoader::QFactoryLoader() looking at "C:/Users/KOT/Documents/Visual Studio 2015/Projects/MoneyManagement/x64/Debug/sqldrivers/qsqlpsqld.dll"
Found metadata in lib C:/Users/KOT/Documents/Visual Studio 2015/Projects/MoneyManagement/x64/Debug/sqldrivers/qsqlpsqld.dll, metadata=
{
    "IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
    "MetaData": {
        "Keys": [
            "QPSQL7",
            "QPSQL"
        ]
    },
    "className": "QPSQLDriverPlugin",
    "debug": true,
    "version": 329216
}


Got keys from plugin meta data ("QPSQL7", "QPSQL")
"15:00:33 : Starting user manager"
loaded library "C:/Users/KOT/Documents/Visual Studio 2015/Projects/MoneyManagement/x64/Debug/sqldrivers/qsqlpsqld.dll"
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\uxtheme.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\dwmapi.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\NapiNSP.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\pnrpnsp.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\nlaapi.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Users\KOT\Documents\Visual Studio 2015\Projects\MoneyManagement\x64\Debug\sqldrivers\qsqlpsqld.dll'. Cannot find or open the PDB file.
'MoneyManagement.exe' (Win32): Loaded 'C:\Users\KOT\Documents\Visual Studio 2015\Projects\MoneyManagement\x64\Debug\libpq.dll'. Cannot find or open the PDB file.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\Wldap32.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Users\KOT\Documents\Visual Studio 2015\Projects\MoneyManagement\x64\Debug\ssleay32.dll'. Cannot find or open the PDB file.
'MoneyManagement.exe' (Win32): Loaded 'C:\Users\KOT\Documents\Visual Studio 2015\Projects\MoneyManagement\x64\Debug\libintl-8.dll'. Module was built without symbols.
'MoneyManagement.exe' (Win32): Loaded 'C:\Users\KOT\Documents\Visual Studio 2015\Projects\MoneyManagement\x64\Debug\libeay32.dll'. Cannot find or open the PDB file.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\secur32.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\msvcr120.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Users\KOT\Documents\Visual Studio 2015\Projects\MoneyManagement\x64\Debug\libiconv-2.dll'. Module was built without symbols.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\sspicli.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\msctf.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\mswsock.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\winrnr.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\wshbth.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\clbcatq.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\DataExchange.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\d3d11.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\dcomp.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\dxgi.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\twinapi.appcore.dll'. Symbols loaded.
'MoneyManagement.exe' (Win32): Loaded 'C:\Windows\System32\bcrypt.dll'. Symbols loaded.
QFactoryLoader::QFactoryLoader() checking directory path "C:/Users/KOT/Documents/Visual Studio 2015/Projects/MoneyManagement/x64/Debug/accessible" ...
QFactoryLoader::QFactoryLoader() checking directory path "C:/Users/KOT/Documents/Visual Studio 2015/Projects/MoneyManagement/x64/Debug/accessiblebridge" ...
"15:00:34 : C:/Users/KOT/Documents/Visual Studio 2015/Projects/MoneyManagement/x64/Debug"
"15:00:34 : Error while connecting to database!"
"15:00:34 : Driver not loaded Driver not loaded"

Thank you for help!

koronabora

I builded psql plugin using msvc compiler with postgres 9.5.2. Nothing changed.

Please, could anybody say how to debug this situation: why plugin is not loading? There are no logs about this.

Thank you!

SGaist

Hi and welcome to devnet,

Do you also have the folder where the PostgreSQL dlls are in your PATH environment variable ? If not, then simply got to the run part of the Project panel and add it there.

koronabora

@SGaist
Yes, global %PATH% includes paths to PostgreSQL's dlls:
https://yadi.sk/i/DP7N4Xx8qvCSB

And these dll is in a root near a project binaries:

ssleay32.dll, iconv.dll, libeay32.dll, libiconv-2.dll, libintl-8.dll, libpq.dll, libxml2.dll, libxslt.dll, zlib1.dll

P.S.

I'm modified psql driver code by appending some output to console, but nothing appears at console after driver loading:

QSqlDriver* QPSQLDriverPlugin::create(const QString &name)
{
    if (name == QLatin1String("QPSQL") || name == QLatin1String("QPSQL7")) {
        QPSQLDriver* driver = new QPSQLDriver();
        std::cout << "Driver loaded by main";
        return driver;
    }
    std::cout << "Driver not loaded by main";
    return 0;
}

SGaist

After re-reading your plugin loading output, there something strange, did you copy the plugin in your application after building it ?

It should rather go in Qt's plugins SQL sub folder

koronabora

I'm sorry.

Using command line to start application:

@echo off
MoneyManagement.exe > out.txt

I see this in file "out.txt":

Driver loaded by main

In lastSqlError variable the same:

Driver not loaded Driver not loaded

And there are no error messages in MSVC output.

What I have to do?

P.S.

After appending debug output to all methods inside "qsql_psql_p.h" I saw this:

Plugin consructor called.
private sql driver constructor called
QPSQLDriver constructor 1
Driver loaded by mainQPSQLDriver close
QPSQLDriver isOpen
QPSQLDriver destructor

SGaist

After re-reading your code sample I just realized: you're using QSqlDatabase wrongly. You are currently trying to open an invalid database object.

addDatabase is a static function. See the detailed description of QSqlDatabase to see how it's done

koronabora

@SGaist

Thank you again!

_sqlBase = new QSqlDatabase();
	*_sqlBase = QSqlDatabase::addDatabase(_SQL_DRIVER); //"QPSQL"

Now all is ok.

SGaist

That's wrong, don't allocate _sqlBase on the heap.

koronabora

@SGaist

Could you explain to me, why?
Thank you.

SGaist

One of the reason is explained in QSqlDatbase::removeDatabase.