main.cpp

/*
c++: 17
deps:
    - org.sw.demo.jtv.pqxx
    - org.sw.demo.apolukhin.magic_get
*/

#include <boost/pfr/precise/core.hpp>
#include <pqxx/pqxx>

int main()
{
    pqxx::connection c("dbname=sw user=webapp password=webapp");

    pqxx::work tx(c);
    /*tx.exec0("CREATE TEMP TABLE str (s text)");
    tx.exec0("INSERT INTO str (s) VALUES ('foo')");

    int i{0};
    std::string out;
    for (std::tuple<std::string> t : reader.iter<std::string>())
    {
        i++;
        out = std::get<0>(t);
    }*/

    c.prepare("x", "select * from package_version");

    auto r = tx.exec_prepared("x");
    for (const auto &row : r)
    {
        // manual way
        struct my_struct { int id, pkgver; };

        my_struct data;
        boost::pfr::for_each_field(data, [&row](auto &field, size_t idx)
        {
            field = row[idx].as<std::decay_t<decltype(field)>>();
        });

        // with macro
#define ASSIGN_PQXX_RESULT(t)                                                                                          \
    t &operator=(const pqxx::row &row)                                                                                 \
    {                                                                                                                  \
        boost::pfr::for_each_field(                                                                                    \
            *this, [&row](auto &field, size_t idx) { field = row[idx].as<std::decay_t<decltype(field)>>(); });         \
        return *this;                                                                                                  \
    }

        struct my_struct2
        {
            int id, pkgver;
            ASSIGN_PQXX_RESULT(my_struct2)
        };
        my_struct2 v;
        v = row;

        //
        std::string x = row[0].c_str();
        auto i = row[0].as<int>();
        /*std::string x = r[0];
        for (std::tuple<std::string> t : r)
        {
        }*/
    }

    return 0;
}