Welcome to taoPQ

taoPQ is a light-weight C++ client library for accessing a PostgreSQL database, providing a modern wrapper for libpq. It has no dependencies beyond a C++17 compatible compiler and the PostgreSQL libpq client library.

Documentation

Version 1.x

Contact

For questions and suggestions regarding taoPQ, success or failure stories, and any other kind of feedback, please feel free to join our Discord server, open a discussion, an issue or a pull request on GitHub or contact the authors at taocpp(at)icemx.net.

Introduction

This library provides classes for database connections and transactions, as well as connection pools and table writers. It also supports for prepared statements and nested transaction. An extensible traits mechanism is used to convert C++ types into SQL statement parameters, and conversely to convert query results into arbitrary C++ types. The following example shows the basic look and feel of the library.

#include <cassert>
#include <iostream>

#include <tao/pq.hpp>

int main()
{
  // Open connection
  const auto conn = tao::pq::connection::create( "dbname=template1" );

  // Execute SQL statement
  conn->execute( "DROP TABLE IF EXISTS taopq_example" );
  conn->execute( "CREATE TABLE taopq_example ( a INTEGER PRIMARY KEY, b INTEGER, c TEXT NOT NULL )" );

  // Prepare statement
  conn->prepare( "my_stmt", "INSERT INTO taopq_example VALUES ( $1, $2, $3 )" );

  {
    // Begin transaction
    const auto tr = conn->transaction();

    // Execute statement with parameters
    tr->execute( "INSERT INTO taopq_example VALUES ( $1, $2, $3 )", 1, 42, "foo" );

    // Execute previously prepared statement with parameters (recommended)
    tr->execute( "my_stmt", 2, tao::pq::null, "Hello, world!" );

    // Commit transaction
    tr->commit();
  }

  // insert/update/delete statements return an object that contains the number of rows affected
  {
    const auto res = conn->execute( "insert", 3, 3, "drei" );
    assert( res.rows_affected() == 1 );
  }

  // Queries return object with result set
  const auto res = conn->execute( "SELECT * FROM taopq_example" );
  assert( res.size() == 3 );

  // Conveniently convert result into C++ container
  const auto v = res.vector< std::tuple< int, std::optional< int >, std::string > >();
}

The Art of C++

taoPQ is part of The Art of C++.

License

taoPQ is certified Open Source software. It may be used for any purpose, including commercial purposes, at absolutely no cost. It is distributed under the terms of the MIT license reproduced here.