db-wrap: A Modern C++ Database Wrapper Library

db-wrap is a lightweight, header-only C++20 library that simplifies database interactions using modern C++ features and concepts. It provides a generic interface for database operations, currently supports only (PostgreSQL) via the libpqxx library.

motivating example: https://www.boost.org/doc/libs/1_86_0/doc/html/boost_pfr.html#boost_pfr.intro

Features

• Type-Safe SQL Queries: Use C++ types directly in queries for better type safety and reduced errors.
• Automatic Parameter Binding: Bind parameters to queries without manual placeholder management.
• Row-to-Object Mapping: Easily convert database rows to user-defined objects using Boost.PFR.
• Compile-Time Query Generation: Optionally generate SQL queries at compile time for performance optimization and validation.

Requirements

• C++20 compatible compiler
• libpqxx library (for PostgreSQL support)
• Boost.PFR library

Installation

db-wrap is a header-only library, so no installation is required. Simply include the header files in your project and link against libpqxx and Boost.PFR.

Usage

Here's a basic example demonstrating how to use db-wrap with libpqxx:

#include <iostream>
#include <string_view>
#include <db_wrap/db_api.hpp>

#include <pqxx/pqxx>

struct User {
    /// `kName` is name table in DB
    static constexpr std::string_view kName = "users";

    int id;
    std::string name;
    std::string email;
};

int main() {
    // Create a connection object
    pqxx::connection conn("postgresql://user:password@host:port/database");

    // Find a user by ID
    auto user = db::find_by_id<User>(conn, 1);
    if (user) {
        std::cout << "User found: " << user->name << std::endl;
    } else {
        std::cout << "User not found!" << std::endl;
    }

    // Retrieve all users
    auto users = db::get_all_records<User>(conn);
    if (users) {
        for (auto&& user : *users) {
            std::cout << "User: " << user.name << " (" << user.email << ")" << std::endl;
        }
    } else {
        std::cout << "No users found!" << std::endl;
    }
}

Examples

More examples can be found in the examples directory.

Testing

Unit tests are provided in the tests directory. You can run the tests using CMake's CTest framework.

Contributing

Contributions are welcome!

License

This library is licensed under the MIT License.