mySQL/README.md

# A library for MySQL that implements a simpler framework for MySQL Connector++

A small framework for basic MySQL database operations via MySQL/Connector++


## Features

- Object oriented
- Active connection pool
- Retries to connect
- Native C++ containers: vector, tuple
- Response object
- Thread safe
- Exceptions
- Can use external periodic maintenance for connection management

## Installation

First install dependency MySQL/Connector++

```
sudo apt install libmysqlcppconn-dev
```

Just download the latest release and unzip it into your project. You can turn it on with:

```
#include "mysql/lib/mysql.hpp"
using namespace marcelb;
```

## Usage

### Internal engine

It internally initializes a single thread that periodically checks the states of the connection pool, adds new ones as needed, and cleans up inactive ones.

```c++

#include "../lib/mysql.hpp"
using namespace marcelb::mysql;

/**
* Init
*/
MySQL mydb("tcp://192.168.2.10:3306", "user_nm", "passss", "my_db", 5);

/**
* Use                                 ------------------              
*/                                   |                  |    
                                 ------------------     |
try {                           |    |              |   |
    // execute                  |    |              |   |
    auto response = mydb.exec<int,string>("SELECT id,domain FROM records WHERE enabled = 0;");
    // response is MySQL_Res<int,string> type
    // check is execute
    cout << response.affected << " " << response.have_result << endl;
    cout << response.rows << " " << response.columns << endl;

    for (auto row : response) { // row is tuple<int,string> type
        cout << get<0>(row) << " " << get<1>(row) << endl;
    }

    // access columns name
    for (auto column_name : response.columns_name) {
        cout << column_name << endl;
    }

} catch (const string err) {
    cout << err << endl;
}
```

### External engine

As I developed quite a few wrappers that have some internal thread, I realized that it was inefficient and made it possible to call the necessary functions periodically outside (one thread per whole application or timer (ASIO), or my asynco wrapper).

```c++
#include "../lib/mysql.hpp"
using namespace marcelb::mysql;

#include "../../asynco/lib/timers.hpp"
using namespace marcelb::asynco;
/**
* Init
*/
MySQL mydb("tcp://192.168.2.10:3306", "user_nm", "passss", "my_db", 5, periodical_engine::external);

periodic mysql_maintenance ( [&mydb] () {
    cout << "IZVRŠAVA SE ENGINE" << endl;
    mydb.periodic_maintenance();
}, MYSQL_PERIODIC_INTERNAL_TIME);

/**
* You can call multiple queries asynchronously                                     
*/                              
                                
auto a1 = atask ( [&mydb] () {
    try {
        auto response =  mydb.exec<int,string>("SELECT id,domain FROM records WHERE enabled = 1;");
        for (auto row : response) {
            cout << get<0>(row) << " " << get<1>(row) << endl;
        }
    } catch (const string err) {
        cout << err << endl;
    }
});

auto a2 = atask ( [&mydb] () {
    try {
        auto response =  mydb.exec<string,string>("SELECT zonename,auth_key FROM zones;");
        for (auto row : response) {
            cout << get<0>(row) << " " << get<1>(row) << endl;
        }
    } catch (const string err) {
        cout << err << endl;
    }
});

auto a3 = atask ( [&mydb] () {
    try {
        auto response =  mydb.exec<string,string>("SELECT username,email FROM users WHERE enabled = 1;");
        for (auto row : response) {
            cout << get<0>(row) << " " << get<1>(row) << endl;
        }
    } catch (const string err) {
        cout << err << endl;
    }
});

wait(a1);
wait(a2);
wait(a3);
```

## To do

- On error, implement virtual/friend function

## License

[APACHE 2.0](http://www.apache.org/licenses/LICENSE-2.0/)


## Support & Feedback

For support and any feedback, contact the address: marcelb96@yahoo.com.

## Contributing

Contributions are always welcome!

Feel free to fork and start working with or without a later pull request. Or contact for suggest and request an option.