MySQL Connector/C++的使用

// g++ -Wall -Werror -std=c++0x -lmysqlclient_r -lmysqlcppconn -o test test.cpp
// create database Contacts;
// create table contacts(uid int unsigned auto_increament key, name varchar(32), phone varchar(32));

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <memory>

#include <mysql_connection.h>
#include <cppconn/driver.h>
#include <cppconn/exception.h>
#include <cppconn/resultset.h>
#include <cppconn/statement.h>

#define DELETE(x) do {if (x) {delete (x); (x) = NULL;}} while(0)

using namespace std;

class MySQLOpr
{
public:
    MySQLOpr() : _con(NULL) {}

    ~MySQLOpr()
    {
        DELETE(_con);
    }

#define SQL_TRY try {
#define SQL_CATCH } catch (sql::SQLException &e) \
        { \
            cerr << "# ERR: SQLException in " << __FILE__; \
            cerr << "(" << __FUNCTION__ << ") on line " << __LINE__ << endl; \
            cerr << "# ERR: " << e.what(); \
            cerr << " (MySQL error code: " << e.getErrorCode(); \
            cerr << ", SQLState: " << e.getSQLState() << " )" << endl; \
        }

    int Connect(const char *addr, const char *user, const char *passwd,
            const char *dbname)
    {
        strncpy(_addr, addr, sizeof(_addr));
        strncpy(_user, user, sizeof(_user));
        strncpy(_passwd, passwd, sizeof(_passwd));
        strncpy(_dbname, dbname, sizeof(_dbname));
        sql::Driver *driver = get_driver_instance();
        DELETE(_con);
        SQL_TRY
            _con = driver->connect(addr, user, passwd);
            _con->setSchema(dbname);
        SQL_CATCH
        if (_con)
            return 0;
        return -1;
    }

    int Update(const char *sql)
    {
        assert(_con != NULL);
        sql::Statement *stmt = NULL;
        int n;
        SQL_TRY
            stmt = _con->createStatement();
            n = stmt->executeUpdate(sql);
        SQL_CATCH
        delete stmt;
        return n;
    }

    unique_ptr<sql::ResultSet> Query(const char *sql)
    {
        assert(_con != NULL);
        sql::Statement *stmt = NULL;
        sql::ResultSet *res = NULL;
        SQL_TRY
            stmt = _con->createStatement();
            res = stmt->executeQuery(sql);
        SQL_CATCH
        cout << "ResultSet ptr " << res << endl;
        return unique_ptr<sql::ResultSet>(res);
    }

private:
    sql::Connection *_con;

    char _addr[64];
    char _user[64];
    char _passwd[64];
    char _dbname[64];

    MySQLOpr(const MySQLOpr &);
    MySQLOpr& operator=(const MySQLOpr &);
};

class DBOperator
{
public:
    static DBOperator& Instance()
    {
        static DBOperator _opr;
        return _opr;
    }

    int Init()
    {
        return contactsOpr.Connect("tcp://127.0.0.1:3307", "user",
                "user", "Contacts");
    }

    int Insert()
    {
        cout << "INSERT" << endl;
        int n = contactsOpr.Update(
                "INSERT INTO contacts VALUES(0, 'user1', '1390000000')");
        n += contactsOpr.Update(
                "INSERT INTO contacts VALUES(0, 'user2', '1380000000')");
        cout << "update " << n << endl;
        return n;
    }

    int Delete()
    {
        cout << "DELETE" << endl;
        int n = contactsOpr.Update(
                "DELETE FROM contacts WHERE name = 'user1'");
        cout << "update " << n << endl;
        return n;
    }

    int Update()
    {
        cout << "UPDATE" << endl;
        int n = contactsOpr.Update(
                "UPDATE contacts SET phone = '1386666666'");
        cout << "update " << n << endl;
        return n;
    }

    int Select()
    {
        cout << "SELECT" << endl;
        unique_ptr<sql::ResultSet> res = contactsOpr.Query(
                "SELECT * FROM contacts");
        if (NULL == res.get())
            return -1;
        while (res->next())
        {
            cout << "Recode: " << res->getInt("uid") << ", "
                << res->getString("name") << ", " << res->getString("phone")
                << endl;
        }
        return 0;
    }

private:
    DBOperator() {}

    MySQLOpr contactsOpr;
};

int main()
{
    DBOperator::Instance().Init();
    DBOperator::Instance().Insert();
    DBOperator::Instance().Select();
    DBOperator::Instance().Update();
    DBOperator::Instance().Select();
    DBOperator::Instance().Delete();
    DBOperator::Instance().Select();
    return 0;
}