MySQL++

I had a need to dump some data I am getting from a real-time sensor network to a database and I choose MySQL - just because it is cheap and cheerful and will fit perfectly with what I am looking for. Now, I have never programmed for MySQL though I have used it in the past as a consumer (e.g. the backend of this blog). MySQL does expose a C API that one can use, but it seems quite arcane to use and does not quite conform to the C++ style (especially when using STL).

It is at that point that I stumbled across MySQL++ - something I had not heard of and of course not used until now. MySQL++ is just a simple C++ wrapper around the same MySQL C API, but it does follow the C++ STL principles and feels more ’natural’ to use. I am still playing with it and getting to know it.

Below is a quick sample on how to connect to a database and retrieve all the records from a table called ‘stock’.

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#include "cmdline.h"
#include "printdata.h"
 
#include <mysql++.h>
 
#include <iostream>
#include <iomanip>
 
using namespace std;
 
int main(int argc, char *argv[])
{
    // Get database access parameters from command line
        const char* db = 0, *server = 0, *user = 0, *pass = "";
    if (!parse_command_line(argc, argv, &db, &server, &user, &pass)) {
        return 1;
    }
 
    // Connect to the sample database.
    mysqlpp::Connection conn(false);
    if (conn.connect(db, server, user, pass)) {
        // Retrieve the sample stock table set up by resetdb
        mysqlpp::Query query = conn.query("select * from stock");
        mysqlpp::StoreQueryResult res = query.store();
 
        // Display results
        if (res) {
            // Display header
            cout.setf(ios::left);
            cout << setw(31) << "Item" <<
                    setw(10) << "Num" <<
                    setw(10) << "Weight" <<
                    setw(10) << "Price" <<
                    "Date" << endl << endl;
 
            // Get each row in result set, and print its contents
            for (size_t i = 0; i < res.num_rows(); ++i) {
                cout << setw(30) << res[i]["item"] << ' ' <<
                        setw(9) << res[i]["num"] << ' ' <<
                        setw(9) << res[i]["weight"] << ' ' <<
                        setw(9) << res[i]["price"] << ' ' <<
                        setw(9) << res[i]["sdate"] <<
                        endl;
            }
        }
        else {
            cerr << "Failed to get stock table: " << query.error() << endl;
            return 1;
        }
 
        return 0;
    }
    else {
        cerr << "DB connection failed: " << conn.error() << endl;
        return 1;
    }
}