libpqxx: Can't compile in Centos7 environment

I am not a native specker, Please forgive me。 I want to add libpqxx as a third part dependence by CMake。but when i use “cmake …” to compile, there are something wrong like this:

here is my project structure:

and here is my CMakeLists.txt:

cmake_minimum_required (VERSION 3.8)

project ("CMPlatformServer" LANGUAGES CXX)

include_directories(
    ${PROJECT_SOURCE_DIR}/src
    ${PROJECT_SOURCE_DIR}/src/server
    ${PROJECT_SOURCE_DIR}/third/workflow/_include/
    ${PROJECT_SOURCE_DIR}/third/libpqxx/include/
)

file(GLOB_RECURSE CODE_SRC  "${PROJECT_SOURCE_DIR}/src/*.h"
                            "${PROJECT_SOURCE_DIR}/src/*.cpp"
                            "${PROJECT_SOURCE_DIR}/src/server/*.h"
                            "${PROJECT_SOURCE_DIR}/src/server/*.cpp")

add_subdirectory(${PROJECT_SOURCE_DIR}/third/workflow)
add_subdirectory(${PROJECT_SOURCE_DIR}/third/libpqxx)

add_executable (CMPlatformServer ${CODE_SRC})

set(LIBPQXX_TARGET_DIRS ${PROJECT_SOURCE_DIR}/third/libpqxx/include/pqxx/)
set(LIBPQXX_INCLUDE_DIRS ${PROJECT_SOURCE_DIR}/third/libpqxx/include/)

target_link_libraries(CMPlatformServer
    PRIVATE workflow-static pthread ssl crypto
    PUBLIC ${LIBPQXX_TARGET_DIRS}
)

target_include_directories(CMPlatformServer ${LIBPQXX_INCLUDE_DIRS})

how can i currently import libpqxx by CMake?