libpqxx | The official C++ client API for PostgreSQL | Database library

I am upgrading an application from using libpqxx 7.1.2 to 7.3.1 and one of the things that have changed in the meantime is that pqxx::binarystring has been deprecated in favour of std::basic_string. My issue is that I use std::vector in C++ to represent a SHA-1 hash, which I then need to store in Postgress as BYTEA. So now I need to find a way to convert std::vector to std::basic_string and back. But I have been unable to find a way to get from vector -> string.

I have been looking at the constructor for std::basic_string and simply cannot figure out how to do it. Amongst other ways to construct std::basic_strig I have tried this, but all give compiler errors error: no matching constructor for initialization of 'std::basic_string'. But when I look at the documentation, I thought the different options I have tried should be legal. So how do I achieve this?

I am learning how to create C aggregate extensions and using libpqxx with C++ on the client side to process the data.

My toy aggregate extension has one argument of type bytea, and the state is also of type bytea. The following is the simplest example of my problem:

Server side:

Hi I'm writing an c++ application using libpqxx to insert rows into a Postgres SQL Table and the data being written is user inputted so I need to guard against SQL injection attacks. From what I see online I can take two approaches:

1. Prepared Statements

env: node: No such file or directory

I checked if my directory for node wasn't wrong and it's fine.

I tried these following answers already: 1. https://github.com/nodejs/node-v0.x-archive/issues/3911 2. https://github.com/creationix/nvm/issues/1702 3. browserify error /usr/bin/env: node: No such file or directory

Related question here and here.

In the Linux GPLv3+ project https://github.com/bstarynk/helpcovid/ (multi-threaded, C++17, web server application) commit b616defc5e54ba869. The need is to be able to terminate gracefully such a web server (interacting with some PostGreSQL database using libpqxx). So issue#35.

I did read both signal(7) and signal-safety(7) and signalfd(2). And I am aware of criticisms against signalfd.

I have a single background C++ std::thread poll(2)-ing on several file descriptors. See file hcv_background.cc where the hcv_start_background_thread function is called from main function in file hcv_main.cc and the created std::thread runs the hcv_background_thread_body function (an event loop doing the poll(2)....)

So hcv_start_background_thread has:

I'm trying to compile libpqxx 7.0.5 and It's having problems finding the postgresql libraries, which I have installed.

I have installed both postgresql and postgresql-libs. Why is giving me this error?.

The configure script stops at this:

For the HelpCovid GPLv3+ web server application (git commit dff3ab1521ed579cbf2 at end of March 2020, probably in function hcv_initialize_database of our file hcv_database.cc) in C++ for Linux (work in progress) using libpqxx with PostgreSQL 11 on Debian/Buster, we would like at startup time to issue one single SQL query which adds a message to the PostGreSQL log file (e.g. /var/log/postgresql/postgresql-11-main.log in our test environment).

The intuition would be that just after creating the tables we would issue some SQL like

--- wrong fictional PostgreSQL query

ADD TO POSTGRESQL LOG FILE ("start of helpcovid pid 1234 commit dff3ab1521ed+ on localhost");

with the hope that something similar to

I want to use this library see: https://github.com/jtv/libpqxx

I decided to install this library manager vcpkg see: https://github.com/microsoft/vcpkg

I set the CMake Option to "CMake projects should use: "-DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/vcpkg/scripts/buildsystems/vcpkg.cmake"

This is the Error:

Stuff used:

Library: libpqxx:x64-windows version 6.4.4

OS: Windows 10

Compiler: Visual C++ (MSVC)

This is my SQL Table: