Solved Implement MongoDB with Qt: mongocxx

[Arush Gupta]

Hi,
I want to implement mongoDB with qt. I could not find a module for mongodb in qt so I went with: http://mongocxx.org/mongocxx-v3/installation/
I installed it and tested it with the command (on test.cpp provided in the link):

c++ test.cpp -o test $(pkg-config --cflags --libs libmongocxx)

and

g++ test.cpp -o test -I/usr/local/include/mongocxx/v_noabi -I/usr/local/include/bsoncxx/v_noabi -L/usr/local/lib -lmongocxx -lbsoncxx

It compiled and ran successfully.
To add this to qt I found this https://forum.qt.io/topic/77841/qt-and-mongocxx-linker-error but using the solution there did not work for me.
Here is my .pro file (relevent part):

#-I/usr/local/include/mongocxx/v_noabi -I/usr/local/include/bsoncxx/v_noabi -L/usr/local/lib -lmongocxx -lbsoncxx
# ^ ouput of: pkg-config --cflags --libs libmongocxx
INCLUDEPATH += \
    -I/usr/local/include/mongocxx/v_noabi \
    -I/usr/local/include/bsoncxx/v_noabi

LIBS += \
    -L/usr/local/lib \
    -lmongocxx \
    -lbsoncxx

I am using arch linux if that makes a difference.
What am I missing here?
Thanks,
Arush

[SGaist]

Hi and welcome to devnet,

What error are you getting exactly ?

[Arush Gupta]

Hi,
I get file not found errors on these lines:

#include <bsoncxx/json.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/stdx.hpp>
#include <mongocxx/uri.hpp>
#include <mongocxx/instance.hpp>

Thanks

[JonB]

@Arush-Gupta
This is not my area, so may not be correct, but while you wait for an expert to comment....

    -I/usr/local/include/mongocxx/v_noabi \
    -I/usr/local/include/bsoncxx/v_noabi

This tells compiler to look in those two directories for files. But your includes read #include <mongocxx/instance.hpp> etc. So to find those paths it needs (presumably) to look down from /usr/local/include to find /usr/local/include/mongocxx/instance.hpp (assuming that is correct). In which case, if compiler does not already look automatically in /usr/local/include (I don't know if it does) you would need -I/usr/local/include?

[Arush Gupta]

Hi,
Thanks for the response
But that does not fix it :(
.pro:

INCLUDEPATH += \
    -I/usr/local/include/

LIBS += \
    -L/usr/local/lib \
    -lmongocxx \
    -lbsoncxx

Thanks

[SGaist]

Where are the files you include located on your hard drive exactly ?

[Arush Gupta]

Hi,
/usr/local/include/mongocxx/v_noabi/ contains folder mongocxx and /usr/local/include/bsoncxx/v_noabi/ contains folder bsoncxx.
Thanks

[SGaist]

I see your issue now. Go back to the original paths you were using but remove the -I before the path, they are unneeded with the INCLUDEPATH variable.

[Arush Gupta]

Hi,
Thanks it worked, I was able to import it, but another issue poped up:

error: 'bsoncxx::v_noabi::builder::stream' has not been declared
   20 | using bsoncxx::builder::stream::close_array;
      |                         ^~~~~~

But I can see folder stream inside builder inside bsoncxx.
In the error I see that it want's to import bsoncxx::v_noabi::builder::stream but I want it to use bsoncxx::v_noabi::bsoncxx::builder::stream
Thanks

[SGaist]

That I do not know.

Can you provide a minimal example that triggers this error ?

[Arush Gupta]

Sorry for the late response,
I solved the issue by reinstalling the packages
Thanks for the help.