Unable to compile SQL plugin

Anton1978 · 1 Apr 2021, 13:37

Good day.
I wrote a small program to understand how Qt c ++ and SQL works.
She writes to me:

QSqlQuery::exec: database not open
QSqlError("", "Driver not loaded", "Driver not loaded")
("QSQLITE", "QODBC", "QODBC3", "QPSQL", "QPSQL7")

After reading the Internet, I found out that I needed a SQL plugin, I found this instruction https://doc.qt.io/qt-5/sql-driver.html#qpsql (Why are plugins not working out of the box? It doesn't matter.)
Ok. I go to the folder ~/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers
Do "qmake -- PSQL_INCDIR=/usr/include/pgsql"
Ok

Running configuration tests...
Done running configuration tests.

Configure summary:

Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... no
  PostgreSQL ............................. yes
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no

Qt is now configured for building. Just run 'make'.
Once everything is built, you must run 'make install'.
Qt will be installed into '/usr'.

Prior to reconfiguration, make sure you remove any leftovers from
the previous build.

Do "make sub-psql"
And I get

cd psql/ && ( test -e Makefile || /usr/lib/qt5/bin/qmake -o Makefile /home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/psql.pro PSQL_INCDIR=/usr/include/pgsql ) && make -f Makefile
make[1]: вход в каталог «/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql»
g++ -c -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -fno-exceptions -Wall -W -Wvla -Wdate-time -Wshift-overflow=2 -Wduplicated-cond -Wno-stringop-overflow -Wno-deprecated-copy -Wno-redundant-move -Wno-format-overflow -Wno-init-list-lifetime -D_REENTRANT -fPIC -DQT_NO_JAVA_STYLE_ITERATORS -DQT_DEPRECATED_WARNINGS -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_CAST_TO_ASCII -DQT_NO_CAST_FROM_ASCII -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_PLUGIN -DQT_SQL_LIB -DQT_CORE_LIB -I. -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.12.8 -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.12.8/QtCore -isystem /usr/include/x86_64-linux-gnu/qt5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore -I.moc -isystem /usr/include/postgresql -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++ -o .obj/qsql_psql.o qsql_psql.cpp
qsql_psql.cpp: In constructor ‘QPSQLDriverPrivate::QPSQLDriverPrivate()’:
qsql_psql.cpp:152:68: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
  152 |     QPSQLDriverPrivate() : QSqlDriverPrivate(QSqlDriver::PostgreSQL) {}
      |                                                                    ^
In file included from qsql_psql.cpp:55:
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:66:5: note: candidate: ‘QSqlDriverPrivate::QSqlDriverPrivate()’
   66 |     QSqlDriverPrivate()
      |     ^~~~~~~~~~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:66:5: note:   candidate expects 0 arguments, 1 provided
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note: candidate: ‘QSqlDriverPrivate::QSqlDriverPrivate(const QSqlDriverPrivate&)’
   61 | class QSqlDriverPrivate : public QObjectPrivate
      |       ^~~~~~~~~~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note:   no known conversion for argument 1 from ‘QSqlDriver::DbmsType’ to ‘const QSqlDriverPrivate&’
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note: candidate: ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriverPrivate&&)’
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note:   no known conversion for argument 1 from ‘QSqlDriver::DbmsType’ to ‘QSqlDriverPrivate&&’
make[1]: *** [Makefile:384: .obj/qsql_psql.o] Error 1
make[1]: выход из каталога «/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql»
make: *** [Makefile:45: sub-psql] Error 2

What's happening? I just need to work with SQL, but that's all. If we open the sqldrivers.pro project using QtCreator, and try to compile, we get 3 errors:

/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp:147: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp:147:73: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
  147 |     inline QSQLiteDriverPrivate() : QSqlDriverPrivate(QSqlDriver::SQLite) {}
      |                                                                         ^

/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/qsql_psql.cpp:152: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/qsql_psql.cpp:152:68: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
  152 |     QPSQLDriverPrivate() : QSqlDriverPrivate(QSqlDriver::PostgreSQL) {}
      |                                                                    ^

:-1: Error: [Makefile:845: .obj/qsql_sqlite.o] Error 1

How do I get the plugin?
I'm using communiti QtCreator, PostgreSQL 13.1 , Ubuntu 20.04

jsulm · 1 Apr 2021, 13:40

@Anton1978 You forgot to mention what database you want to use actually?
Looks like you want to use PostgreSQL. If this is the case there is no need to build anything, the plug-in is delivered with Qt (libqsqlpsql.so).
For MySQL you have to build it by yourself because of MySQL license reasons.
If the plug-in is not loaded then do this: set QT_DEBUG_PLUGINS env variable and then start your app. I guess PostgreSQL client library is not installed.

Anton1978 · 1 Apr 2021, 15:00

@jsulm Yes, use PostgreSQL. If i enter the command "sudo apt install postgresql-client-13"
then the terminal writes "The most recent version of postgresql-client-13 package (13.1-1.pgdg20.04 + 1) is already installed.
postgresql-client-13 is marked as manually installed."

the output after export QT_DEBUG_PLUGINS = 1 is huge, even larger than the code of the program itself.
Here it is, what would you advise to look for there?

https://cloud.mail.ru/public/3tnm/Zn2pjp1qr

Christian Ehrlicher · wrote on 4 Jan 2021, 17:31

You called the wrong qmake so the wrong headers are picked up. Call the qmake from your Qt version you're trying to compile the plugin for (I would guess it's 5.15 and not 5.12).
Same problem here: https://forum.qt.io/topic/121095/issues-connecting-qt-to-mysql/9

Anton1978 · wrote on 4 Jan 2021, 17:42

tried to do so
'~/Qt/5.15.2/gcc_64/bin/qmake -- PSQL_INCDIR=/usr/include/pgsql'
Ok

anton@home:~/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers$ ~/Qt/5.15.2/gcc_64/bin/qmake -- PSQL_INCDIR=/usr/include/pgsql

Running configuration tests...
Done running configuration tests.

Configure summary:

Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... no
  PostgreSQL ............................. yes
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no

Qt is now configured for building. Just run 'make'.
Once everything is built, you must run 'make install'.
Qt will be installed into '/home/anton/Qt/5.15.2/gcc_64'.

Prior to reconfiguration, make sure you remove any leftovers from
the previous build.

Ok, do it 'make sub-psql'
And...

anton@home:~/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers$ make sub-psql
cd psql/ && ( test -e Makefile || /home/anton/Qt/5.15.2/gcc_64/bin/qmake -o Makefile /home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/psql.pro ) && make -f Makefile
make[1]: вход в каталог «/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql»
g++ -c -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -O2 -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -fno-exceptions -Wall -W -Wvla -Wdate-time -Wshift-overflow=2 -Wduplicated-cond -Wno-stringop-overflow -Wno-deprecated-copy -Wno-redundant-move -Wno-format-overflow -Wno-init-list-lifetime -D_REENTRANT -fPIC -DQT_NO_JAVA_STYLE_ITERATORS -DQT_DEPRECATED_WARNINGS -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_CAST_TO_ASCII -DQT_NO_CAST_FROM_ASCII -DQT_NO_EXCEPTIONS -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -DQT_NO_DEBUG -DQT_PLUGIN -DQT_SQL_LIB -DQT_CORE_LIB -I. -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.12.8 -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore/5.12.8/QtCore -isystem /usr/include/x86_64-linux-gnu/qt5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtSql -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore -I.moc -isystem /usr/include/postgresql -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++ -o .obj/qsql_psql.o qsql_psql.cpp
qsql_psql.cpp: In constructor ‘QPSQLDriverPrivate::QPSQLDriverPrivate()’:
qsql_psql.cpp:152:68: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
  152 |     QPSQLDriverPrivate() : QSqlDriverPrivate(QSqlDriver::PostgreSQL) {}
      |                                                                    ^
In file included from qsql_psql.cpp:55:
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:66:5: note: candidate: ‘QSqlDriverPrivate::QSqlDriverPrivate()’
   66 |     QSqlDriverPrivate()
      |     ^~~~~~~~~~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:66:5: note:   candidate expects 0 arguments, 1 provided
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note: candidate: ‘QSqlDriverPrivate::QSqlDriverPrivate(const QSqlDriverPrivate&)’
   61 | class QSqlDriverPrivate : public QObjectPrivate
      |       ^~~~~~~~~~~~~~~~~
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note:   no known conversion for argument 1 from ‘QSqlDriver::DbmsType’ to ‘const QSqlDriverPrivate&’
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note: candidate: ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriverPrivate&&)’
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h:61:7: note:   no known conversion for argument 1 from ‘QSqlDriver::DbmsType’ to ‘QSqlDriverPrivate&&’
make[1]: *** [Makefile:384: .obj/qsql_psql.o] Ошибка 1
make[1]: выход из каталога «/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql»
make: *** [Makefile:45: sub-psql] Ошибка 2

it looks like mockery

Christian Ehrlicher · wrote on 4 Jan 2021, 17:48

@Anton1978 said in Unable to compile SQL plugin:

/usr/include/x86_64-linux-gnu/qt5/QtCore/5.12.8

Still using the wrong include paths. Make sure to start with a clean source dir.

Anton1978 · wrote on 4 Jan 2021, 18:08

I really don't understand why this is happening? I am explicitly specifying which qmake to use - '~/Qt/5.15.2/gcc_64/bin/qmake'
Even if I write like this
~/Qt/5.15.2/gcc_64/bin/qmake -- PSQL_INCDIR=~/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers
the result does not change
why is the file used
/usr/include/x86_64-linux-gnu/qt5/QtSql/5.12.8/QtSql/private/qsqldriver_p.h

I think me need some rest

Anton1978 · 1 Apr 2021, 18:27

Another interesting point, if you open the SQLPlagin project in QTCreator, you can see that the sources with errors
/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/sqldrivers.pro
have 3 errors

/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/qsql_psql.cpp:152: error: no matching constructor for initialization of 'QSqlDriverPrivate' 

:-1: error: [Makefile:845: .obj/qsql_sqlite.o] Error 1

/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/qsql_psql.cpp:152: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
/home/anton/Qt/5.15.2/Src/qtbase/src/plugins/sqldrivers/psql/qsql_psql.cpp:152:68: error: no matching function for call to ‘QSqlDriverPrivate::QSqlDriverPrivate(QSqlDriver::DbmsType)’
  152 |     QPSQLDriverPrivate() : QSqlDriverPrivate(QSqlDriver::PostgreSQL) {}

He writes to me about these errors when using make.
But for others it compiles.
Some kind of mysticism.

Christian Ehrlicher · wrote on 4 Jan 2021, 18:39

Again: start with a clean source dir and call the correct qmake.

eyllanesc · 1 Apr 2021, 19:00

It is not necessary to compile the plugin but it is only necessary to install the client, in the case of Ubuntu it is enough with:

sudo apt-get install libpq-dev

Anton1978 · 4 Jan 2021, 20:28

@eyllanesc
It's installed, everything doesn't work

SGaist · wrote on 4 Jan 2021, 19:24

Hi,

As @Christian-Ehrlicher wrote, you have to clean the sources before starting fresh. There are also hidden files in the folder that you need to remove (you can find that here).

If you want to be on the safe side, you can even to an out of source build.

eyllanesc · 4 Jan 2021, 20:39

@Anton1978 It is very strange since I have tested an example in GH actions and it works correctly for me, on the other hand if you want to compile it recommends you delete the files generated by your incorrect execution. You can also follow my answer in SO:https://stackoverflow.com/a/65568190/6622587

Anton1978 · 5 Jan 2021, 07:21

@eyllanesc said in Unable to compile SQL plugin:

@Anton1978 It is very strange since I have tested an example in GH actions and it works correctly for me, on the other hand if you want to compile it recommends you delete the files generated by your incorrect execution. You can also follow my answer in SO:https://stackoverflow.com/a/65568190/6622587

This my question too)). The second day I am at war with this plugin.
Thanks for prompting me to git this plugin, it really helped, now it remains to figure out how to connect the compiled plugin to my QtCreator.

jsulm · wrote on 5 Jan 2021, 07:21

@Anton1978 said in Unable to compile SQL plugin:

how to connect the compiled plugin to my QtCreator

You only need to call "make install" after make, then it should work.

It would be interesting to know why the preinstalled plug-in doesn't work. To do so set QT_DEBUG_PLUGINS=1 before starting your app. Then you should see what is happening.