libpqxx on raspberry pi

I have a desktop QT application which uses libpqxx(c++ library or Postgres). The GUI app is an interface to the postgress database and does a lot of operations. Now, I am trying to port this application to a raspberry pi3. I started with a test QT app. Used cross-compile tool chain to build the test app on desktop and deployed it on pi. It works like a charm. However, when I follow the same steps to deploy my actual app on pi, its giving me compile time error

fatal error: pqxx/pqxx: No such file directory.

I have the library linked in .pro file via -lpqxx -lpq. I have also installed libpqxx on pi3. It works on my desktop with Qt 5.6.1 GCC 64 bit kit but doesn't work on pi with Rpi3 Qt kit. Please help.