Neuroshok Database Interface

	gcc8.1 / clang8.0 / msvc19.16
Master
Dev

ndb is a generic interface to connect to any database. Queries are written in pure C++ and can be executed on different database engines just by changing one parameter. Database model is defined and accessible at compile time.

Features

• Header only interface
• Full C++ and generic queries
• Support any type of databases
• Easy to add new engines
• Compile-time generation for SQL expressions
• Customizable types conversion
• Field access by C++ structure
• Database generation with macros

Current support

• Expressions based on SQL and BSON
• Sqlite, PostgreSQL and MongoDB.

How to use

Choose the branch to clone (master or dev)

ads@NK:/home/ads$ git clone -b [branch] https://github.com/ads00/ndb.git

Build (optional)

Create build directory

ads@NK:/home/ads/ndb$ mkdir build && cd build

Bundled engines

Choose engines with option -DNDB_ENGINE_[name]=ON (ex: -DNDB_ENGINE_SQLITE=ON)

Options

-DNDB_BUILD_TEST=ON -DNDB_BUILD_EXAMPLE=ON

ads@NK:/home/ads/ndb/build$ cmake -DNDB_ENGINE_SQLITE=ON [options] -DCMAKE_BUILD_TYPE=Release ..
ads@NK:/home/ads/ndb/build$ make
(optional) ads@NK:/home/ads/ndb/build$ make test

Integration

CMake

add_subdirectory(${PATH_TO_NDB}/ndb ${THIRD_PARTY_ROOT}/ndb/cmake-build)
target_link_libraries(my_target lib_ndb)

Manual

Add paths to ndb headers and your custom engine builds

Overview

Database

ndb_table(movie,
          ndb_field_id,
          ndb_field(name, std::string, ndb::size<255>)
)
ndb_table(music,
          ndb_field_id,
          ndb_field(image, std::string, ndb::size<255>)
)
ndb_model(collection, movie, music)

ndb_project(my_project,
            ndb_database(libray, collection, ndb::sqlite),
            ndb_database(mongo_library, collection, ndb::mongo)
)

Queries

ndb::query<dbs::zeta>() << ( movie.id, movie.image ); // get
ndb::query<dbs::zeta>() << ( movie.id == a && movie.name == b ); // get by condition
ndb::query<dbs::zeta>() >> (( movie.name = "updated") << ( movie.id == 3 )); // update by condition
ndb::query<dbs::zeta>() + ( movie.id = 3, movie.name = "test" ); // add
ndb::query<dbs::zeta>() - ( movie.id == 3 ); // del

Example

An example with a libray database using a collection model and a movie table

#include "my_database.h"

// aliases
namespace dbs
{
    using libray = ndb::databases::my_project::libray_;
    using mongo_library = ndb::databases::my_project::mongo_library_;
}

int main()
{
    // alias
    const auto& movie = ndb::models::collection.movie;
    
    // initialize sqlite and mongo
    ndb::initializer<ndb::sqlite, ndb::mongo> init;
    
    // connect to database library (sqlite is used)
    ndb::connect<dbs::library>();
    
    // connect to database mongo_library (mongo is used)
    ndb::connect<dbs::mongo_library>();  

    // add a movie with specified movie.name and movie.duration (table is deduced compile time)
    ndb::query<dbs::library>() + (movie.name = "Interstellar", movie.duration = 2.49_h) );
    
    // get all fields from movie where duration is less than 2H30
    for (auto& line : ndb::query<dbs::library>() << (movie.duration <= 3.30_h))
    {
        std::cout << "movie.name : " << line[movie.name] << std::endl;
        std::cout << "movie.duration : " << line[movie.duration] << std::endl; 
    }

    return 0;
}

Documentation

Example

Contribution

ads00

Jonathan Poelen (@jonathanpoelen)