在Windows 10上从Visual Studio 2015链接libpqxx

Question

I've recently decided to try out PostgreSQL as the database platform for some C++ development I'm working on. I decided to use libpqxx as the connection library for my project, and quickly found out this would be an uphill battle to do from VS 2015 on a Windows 10 machine.

After much teeth-gnashing and nail-biting, I have gotten libpqxx to compile on Windows 10. This leaves me with the following directory structure

Per libpqxx's documentation, I also placed a copy of libpq.dll in my project's executable directory. Please note: I have done this for both debug and release builds, tried to build both, and ended up with the same result.

All the tutorials I've seen seem to indicate that the library can be used after linking it and simply #including pqxx/pqxx, so I set up a small project to do just that. I receive the error:

fatal error C1083: Cannot open include file: 'pqxx/pqxx': No such file or directory

When attempting to build the project. I have also tried this will both debug and release builds, to no avail.

Here is a screenshot of my linker settings.

Does anyone have any suggestions for how I might be able to link and use this library from Visual Studio 2015?

Answer 1

As Sami Kuhmonen pointed out, this was not actually a linker error, but a compiler error. I needed to include an actual header, which Visual Studio needed to be able to find. After adding the correct folder (C:\\libpqxx\\include in my case) to Visual Studio's "additional include directories" setting under C\\C++ -> General per drescherjm's suggestion, the program compiles just fine.

For future reference: I did also run into unresolved external linker errors after solving the initial issue. This is because you need to make sure to also link to ws2_32.lib and libpq.lib. You also need to copy some other DLL files that libpq also relies on into your libpqxx lib folder. On my system, I believe these were ssleay32.dll, libeay32.dll, and libintl-8.dll. These files reside under the root of the PostgreSQL install. The DLL step is mentioned under libpqxx's INSTALL.txt file, however I believe it stated that the DLLs resided one folder under where I actually found them.

Answer 2

I have also faced same issue. Then I realized that I was building ,my application as a 32bit. I changed the target to x64 and it compiled successfully