MySQL-C++封装类

MySQLInterface.h：

// MySQLInterface

// 功能描述：实现对MySQL访问操作的封装

#ifndef __MYSQL_INTERFACE_H__  
#define __MYSQL_INTERFACE_H__  

#include   
#include   

#include  // 远程访问
#include "MySQL/include/mysql.h"

// 引入相关库
#pragma comment(lib, "ws2_32.lib")  
#pragma comment(lib, "MySQL/lib/libmysql.lib")

#define ERROR_QUERY_FAIL -1 // 操作失败


// 定义MySQL连接信息
typedef struct
{
	char* server;
	char* user;
	char* password;
	char* database;
	int port;
}MySQLConInfo;

class MySQLInterface
{
public:
	MySQLInterface();
	virtual ~MySQLInterface();

	void SetMySQLConInfo(char* server, char* username, char* password, char* database, int port);// 设置连接信息
	bool Open();  // 打开连接
	void Close(); // 关闭连接

	bool Select(const std::string& Querystr, std::vector >& data);	     // 读取数据
	bool Query(const std::string& Querystr);     // 其他操作
	int GetInsertID(const std::string& Querystr);// 插入并获取插入的ID,针对自动递增ID
	void ErrorIntoMySQL();		 // 错误消息

public:
	int ErrorNum;				 // 错误代号  
	const char* ErrorInfo;       // 错误提示  

private:
	MySQLConInfo MysqlConInfo;	 // 连接信息
	MYSQL MysqlInstance;		 // MySQL对象
	MYSQL_RES *Result;			 // 用于存放结果 
};

#endif  

MySQLInterface.cpp:

#include "stdafx.h"  
#include "MySQLInterface.h"  


MySQLInterface::MySQLInterface() :
ErrorNum(0), ErrorInfo("ok")
{
	mysql_library_init(0, NULL, NULL);
	mysql_init(&MysqlInstance);

	// 设置字符集，否则无法处理中文
	mysql_options(&MysqlInstance, MYSQL_SET_CHARSET_NAME, "gbk");
}

MySQLInterface::~MySQLInterface()
{
}

// 设置连接信息
void MySQLInterface::SetMySQLConInfo(char* server, char* username, char* password, char* database, int port)
{
	MysqlConInfo.server = server;
	MysqlConInfo.user = username;
	MysqlConInfo.password = password;
	MysqlConInfo.database = database;
	MysqlConInfo.port = port;
}

// 打开连接
bool MySQLInterface::Open()
{
	if (mysql_real_connect(&MysqlInstance, MysqlConInfo.server, MysqlConInfo.user,
		MysqlConInfo.password, MysqlConInfo.database, MysqlConInfo.port, 0, 0) != NULL)
	{
		return true;
	}
	else
	{
		ErrorIntoMySQL();
		return false;
	}
}

// 断开连接
void MySQLInterface::Close()
{
	mysql_close(&MysqlInstance);
}

//读取数据
bool MySQLInterface::Select(const std::string& Querystr, std::vector >& data)
{
	if (0 != mysql_query(&MysqlInstance, Querystr.c_str()))
	{
		ErrorIntoMySQL();
		return false;
	}

	Result = mysql_store_result(&MysqlInstance);

	// 行列数
	int row = mysql_num_rows(Result);
	int field = mysql_num_fields(Result);

	MYSQL_ROW line = NULL;
	line = mysql_fetch_row(Result);

	int j = 0;
	std::string temp;
	std::vector >().swap(data);
	while (NULL != line)
	{
		std::vector linedata;
		for (int i = 0; i < field; i++)
		{
			if (line[i])
			{
				temp = line[i];
				linedata.push_back(temp);
			}
			else
			{
				temp = "";
				linedata.push_back(temp);
			}
		}
		line = mysql_fetch_row(Result);
		data.push_back(linedata);
	}
	return true;
}

// 其他操作
bool MySQLInterface::Query(const std::string& Querystr)
{
	if (0 == mysql_query(&MysqlInstance, Querystr.c_str()))
	{
		return true;
	}
	ErrorIntoMySQL();
	return false;
}

// 插入并获取插入的ID,针对自动递增ID
int MySQLInterface::GetInsertID(const std::string& Querystr)
{
	if (!Query(Querystr))
	{
		ErrorIntoMySQL();
		return ERROR_QUERY_FAIL;
	}
	// 获取ID
	return mysql_insert_id(&MysqlInstance);
}

//错误信息
void MySQLInterface::ErrorIntoMySQL()
{
	ErrorNum = mysql_errno(&MysqlInstance);
	ErrorInfo = mysql_error(&MysqlInstance);
}

Example

#include using namespace std;   #include "MySQLInterface.h"    int _tmain(int argc, _TCHAR* argv[]) {          MySQLInterface MySQLInterface;          MySQLInterface.SetMySQLConInfo("localhost", "root", "123456", "world", 337);          if (!MySQLInterface.Open())          {                   std::cout << MySQLInterface.ErrorNum << " : " << MySQLInterface.ErrorInfo << std::endl;          }            // 读取数据          std::vector > data;          std::string sqlstr = "SELECT `ID`,`Name`,`CountryCode`,`District` FROM `world`.`city` LIMIT 10";          MySQLInterface.Select(sqlstr, data);            // 显示数据          for (unsigned int i = 0; i < data.size(); ++i)          {                   for (unsigned int j = 0; j < data[0].size(); ++j)                   {                           cout << data[i][j] << "\t\t";                   }                   cout << endl;          }            // 其他操作          sqlstr = "CREATE TABLE IF NOT EXISTS `new_paper` (";          sqlstr += " `NewID` int(11) NOT NULL AUTO_INCREMENT,";          sqlstr += " `NewCaption` varchar(40) NOT NULL,";          sqlstr += " `NewContent` text,";          sqlstr += " `NewTime` datetime DEFAULT NULL,";          sqlstr += " PRIMARY KEY(`NewID`)";          sqlstr += " ) ENGINE = InnoDB DEFAULT CHARSET = utf8";            if (!MySQLInterface.Query(sqlstr))          {                   std::cout << MySQLInterface.ErrorNum << " : " << MySQLInterface.ErrorInfo << std::endl;          }            MySQLInterface.Close();            system("pause");          return 0; }

 

错误提示

MFC (CString)

if (!m_MySQLInter.Open()) // 连接失败     {          CString strError = _T("");          USES_CONVERSION;          strError.Format(_T("打开数据库失败...\n%d : %s"), m_MySQLInter.ErrorNum, A2W(m_MySQLInter.ErrorInfo));          ::MessageBox(GetSafeHwnd(), strError, _T("系统提示"), MB_ICONEXCLAMATION | MB_OK);          return;     }

 

Win32

         if(!m_MySQLInter.Open())

         {

                  std::cout<< m_MySQLInter.ErrorNum << " : " <

                  return;

         }

 

 

类型转换

Std::string to char*

// 类型转换          char* pDatabase = new char[strlen(database.c_str()) + 1];          strcpy(pDatabase, database.c_str());          char* pPassword = new char[strlen(password.c_str()) + 1];          strcpy(pPassword, password.c_str());          char* pUserName = new char[strlen(usename.c_str()) + 1];          strcpy(pUserName, usename.c_str());          char* pServer = new char[strlen(server.c_str()) + 1];          strcpy(pServer, server.c_str());            m_MySQLInter.SetMySQLConInfo(pServer, pUserName, pPassword, pDatabase, port);

 

CString to char*

USES_CONVERSION;     m_MySQLInter.SetMySQLConInfo(W2A(m_strServer), W2A(m_strUserName), W2A(m_strPassword), "log", _ttoi(m_strPort));       if (!m_MySQLInter.Open()) // 连接失败     {          CString strError = _T("");          USES_CONVERSION;          strError.Format(_T("打开数据库失败...\n%d : %s"), m_MySQLInter.ErrorNum, A2W(m_MySQLInter.ErrorInfo));          ::MessageBox(GetSafeHwnd(), strError, _T("系统提示"), MB_ICONEXCLAMATION | MB_OK);          return;     }