MySQL

安装官方提供的mysqlconnect后，可以使用mysql++库，在官方的C API上再次做一个c++面向对象封装。

这里mysql++的安装依赖于mysql-connector-c。安装参考：http://dev.mysql.com/doc/connector-c/en/connector-c-installation-source-unix.html

c++11下注意：

1.由于mysql++并没有采用c++11，所以在使用的时候报了一些警告，需要对源码进行修改。

2.在获取字段类型的API在g++编译器下不是非常理想

3.执行sql存在错误时，系统会coredump，注意try语句的使用

下面部分代码：

#pragma once
#include "mysql++.h"

#define MYSQL_CFG_FILE "..//..//common//MySQL//config.json"


typedef struct mysql_config
{
    std::string ip;
    int port;
    std::string user;
    std::string passwd;
    std::string database_name;
}mysql_cfg;

typedef struct mysql_field_information
{
    std::string Field;
    std::string Type;
    std::string Null;
    std::string Key;
    std::string Default;
    std::string Extra;
}mysql_field_info;

typedef std::vector<mysql_field_info> mysql_table_info;

typedef struct mysql_field_data
{
    
    short SHORT;
    int INTEGER;
    long long BIGINT;
    float FLOAT;
    double DOUBLE;
   
    std::string DATETIME;
   
    std::string VARCHAR;
}mysql_field;

typedef std::map<std::string, std::vector<mysql_field>> mysql_table; 

enum mysql_database_info
{
    SHOW_VERISON,
    SHOW_DATABASES,
    SHOW_TABLES
};

class DMMySQL
{
public:
    DMMySQL();
    ~DMMySQL();

    void show_databases_info(int flag, std::vector<std::string>& databases);

    bool get_table_desc(std::string table_name, mysql_table_info& table_info);

    bool insert_mysql(std::string sql);
    
    bool insert_mysql(std::string table_name, std::map<std::string, std::string>& insert_data);
    
    bool update_mysql(std::string sql);

    bool update_mysql(std::string table_name, std::string field_name, std::string field_value,
        std::string filter_key, std::string filter_value);

    bool select_mysql(std::string table_name, mysql_table& table_data);

    bool select_mysql(std::string table_name, std::string field_name, std::vector<mysql_field>& field_data);

    bool select_mysql(std::string table_name, std::string field_name, 
        std::string filter_key, std::string filter_value, 
        std::vector<mysql_field>& field_data, std::string filter_opt = "=");
    
private:
    bool load_mysql_config();
    
    void init();
     
    bool conncet_mysql();

    void disconnect_mysql();

    void trans_data_type(std::string input_data, std::string data_type, mysql_field& field_data);

private:
    mysql_cfg _mysql_cfg;
    mysqlpp::Connection _conn;
};

#include "json/json.h"
#include <fstream>
#include <ace/Log_Msg.h>
#include "DMMySQL.h"
#include <cxxabi.h>

#define TRY_SQL 
    try{
    
#define CATCH_SQL_ERROR 
}
catch(const mysqlpp::BadQuery& error)
{
    ACE_DEBUG((LM_ERROR,"MySQL Query error:%s!
",error.what()));
    return false;
}
catch (const mysqlpp::BadConversion& error)
{
    ACE_DEBUG((LM_ERROR,"MySQL Conversion error:%s!
",error.what()));
    return false;
}
catch (const mysqlpp::Exception& error)
{
    ACE_DEBUG((LM_ERROR,"MySQL Exception error:%s!
",error.what()));
    return false;
}

DMMySQL::DMMySQL()
{
    init();
}

DMMySQL::~DMMySQL()
{
    disconnect_mysql();
}

bool DMMySQL::load_mysql_config()
{
    std::ifstream cfg_file;
    cfg_file.open(MYSQL_CFG_FILE, std::ios::binary);

    if (!cfg_file.is_open())
    { 
        return 0;
    }

    Json::Reader Reader;
    Json::Value Root;

    if (Reader.parse(cfg_file,Root))
    {
        _mysql_cfg.ip = Root["mysql_ip"].asString();
        _mysql_cfg.port = Root["mysql_port"].asInt();
        _mysql_cfg.user = Root["mysql_user"].asString();
        _mysql_cfg.passwd = Root["mysql_passwd"].asString();
        _mysql_cfg.database_name = Root["database_name"].asString();
    }
    else
    {
        ACE_DEBUG((LM_ERROR,"parse mysql config file failure!
"));    
        return false;
    }
    
    return true;
}

void DMMySQL::init()
{
    if (load_mysql_config())
    {
        conncet_mysql();
    }
}

bool DMMySQL::conncet_mysql()
{ 
    if (!_conn.connect(_mysql_cfg.database_name.c_str(), _mysql_cfg.ip.c_str(),
        _mysql_cfg.user.c_str(), _mysql_cfg.passwd.c_str(), _mysql_cfg.port))
    {
        ACE_DEBUG((LM_ERROR,"connect MySQL database failure!
"));    
        return false;
    }

    return true;
}

void DMMySQL::show_databases_info(int flag, std::vector<std::string>& databases)
{
    std::string opration;    
   
    switch (flag)
    {
    case SHOW_VERISON:
        {
            std::string version_info = _conn.client_version();
            databases.push_back(version_info);
            return;
        }
    case SHOW_DATABASES:
        {
            opration = "show databases";
            break; 
        }
    case SHOW_TABLES:
        {
            
            opration = "show tables";
            break; 
        }
    default:
        {
            return;
        }
    }

    mysqlpp::Query query = _conn.query(opration);
    if (mysqlpp::StoreQueryResult res = query.store())
    {           
        mysqlpp::StoreQueryResult::iterator rit;    
        for (rit = res.begin(); rit != res.end(); ++rit) 
        {
            databases.push_back((*rit)[0].c_str());
        }    
    }
}

bool DMMySQL::get_table_desc(std::string table_name, mysql_table_info& tbl_info)
{
    TRY_SQL
    std::string opration = "describe " + table_name;    
    mysqlpp::Query query = _conn.query(opration);
    mysqlpp::StoreQueryResult res = query.store();

    int field_num = res.size();
    for (int i = 0; i < field_num; ++i)
    {
        mysql_field_info field_i;
        
        field_i.Field   = res[i]["field"].c_str();
        field_i.Type    = res[i]["type"].c_str();
        field_i.Null    = res[i]["null"].c_str();
        field_i.Key     = res[i]["key"].c_str();
        field_i.Default = res[i]["default"].c_str();
        field_i.Extra   = res[i]["extra"].c_str();
        
        tbl_info.push_back(field_i);
    }
    CATCH_SQL_ERROR
    return true;
}

void DMMySQL::disconnect_mysql()
{
    _conn.disconnect();
}

bool DMMySQL::insert_mysql(std::string sql)
{
    TRY_SQL
    mysqlpp::Query query = _conn.query(sql);
    query.execute();
    CATCH_SQL_ERROR
    return true;
}

完整代码参考：https://github.com/binchen-china/DMServer