mysqlcapi简单连接池_MySQL

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连接池为了解决频繁的创建、销毁所带来的系统开销。

简而言之，就是 自己先创建一定量的连接，然后在需要的时候取出一条连接使用。

当然如果你只有一个线程连接数据库，而且不是实时返回结果，那么你完全不必用连接池。

想一下网络大型游戏服务器，你就明白为什么需要连接池了。

自己敲代码写了一个简单的类，实现连接池，虽然没有mysql++那么强大，但是还是自己有收获。

Csqlpool.h 头文件实现如下：

 

#pragma once#include <WinSock2.h>#include <mysql.h>#include <list>#pragma comment( lib , "libmysql.lib" )using namespace std;class Csqlpool{public:	~Csqlpool(void);	static Csqlpool *GetSqlPool();	bool IniSqlPool( const char *host , const char *name , const char *pwd , unsigned int port , unsigned int conMax );  //初始化连接池	bool SelectDB( MYSQL *sql, const char *DB);	//选择数据库	MYSQL *GetConnect();          // 获取连接	void RelConnect(MYSQL *sql) ;  // 释放连接	MYSQL_RES* GetQuery( MYSQL *sql , const char *query);      //mysql操作  增删查改	void RelQuery(MYSQL_RES *res);   //释放MYSQL_RES资源	bool Query(MYSQL *sql , const char *query);  //增、删、改操作protected:	Csqlpool(void);private:	list<MYSQL *> m_sql_free;   //空闲连接     	static Csqlpool *pSqlPool;      	CRITICAL_SECTION m_session;    //获取空闲线程};

Csqlpool.cpp 实现如下：

#include "StdAfx.h"#include "Csqlpool.h"Csqlpool *Csqlpool::pSqlPool = NULL;Csqlpool::Csqlpool(void){	InitializeCriticalSection( &m_session );}Csqlpool::~Csqlpool(void){	while ( m_sql_free.size() )	{		mysql_close( m_sql_free.front() );		m_sql_free.pop_front();	}	DeleteCriticalSection(&m_session);}Csqlpool* Csqlpool::GetSqlPool(){	if (  pSqlPool == NULL )	{		return new Csqlpool;	}	return pSqlPool;}bool Csqlpool::IniSqlPool( const char *host ,const char *name , const char *pwd , unsigned int port , unsigned int conMax )  //初始化连接池{	int nsum = 0 ;	for (unsigned int i = 0 ; i < conMax ;++i  )	{		MYSQL *pmysql;		pmysql = mysql_init( (MYSQL*)NULL );		if ( pmysql != NULL )		{			if ( mysql_real_connect( pmysql , host , name , pwd , NULL , 3306 , NULL , 0 ) )			{				m_sql_free.push_back(pmysql);			}			else			{				if ( nsum++ == 100 )				{					return false;				}				continue;			}		}		continue;	}	return true;}bool Csqlpool::SelectDB( MYSQL *sql, const char *DB)	//选择数据库{	if(mysql_select_db(sql , DB))	{		return false;	}	return true;}MYSQL* Csqlpool::GetConnect()          // 获取连接{	if ( m_sql_free.size()  )	{		EnterCriticalSection(&m_session);		MYSQL *mysql = m_sql_free.front();		m_sql_free.pop_front();		LeaveCriticalSection(&m_session);		return mysql;	}	else		return NULL;}void Csqlpool::RelConnect(MYSQL *sql)  // 释放连接{	EnterCriticalSection(&m_session);	m_sql_free.push_back(sql);	LeaveCriticalSection(&m_session);}MYSQL_RES* Csqlpool::GetQuery( MYSQL *sql , const char *query)         //查询操作{	if ( mysql_query( sql , query ) == 0 )	{		return mysql_store_result( sql );	}	else		return NULL;}void Csqlpool::RelQuery(MYSQL_RES *res)   //mysql_res release{	mysql_free_result(res);}bool Csqlpool::Query(MYSQL *sql , const char *query)  //增、删、改操作{	if ( mysql_query( sql , query ) )	{		return false;	}	return true;}

testsqlpool.cpp 测试文件实现如下：

// testsqlpool.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include "Csqlpool.h"#include <iostream>using namespace std;Csqlpool *psql = Csqlpool::GetSqlPool();DWORD WINAPI ThreadProc( LPVOID lpParameter);int _tmain(int argc, _TCHAR* argv[]){	if(!psql->IniSqlPool("127.0.0.1" , "root" ,"123",3306,10))	{		cout<<"连接错误"<<endl;	}	HANDLE phan[2] ;	DWORD threadid[2];	int n1 = 0, n2 = 100;;	phan[0]  = CreateThread( NULL , 0 ,  ThreadProc , &n1 ,  0 , &threadid[0] );	phan[1]  = CreateThread( NULL , 0 , ThreadProc , &n2 ,   0 , &threadid[1] );	WaitForMultipleObjects( 2 , phan , true ,  INFINITE );	CloseHandle(phan[0]);	CloseHandle(phan[1]);	return 0;}DWORD WINAPI ThreadProc( LPVOID lpParameter){	int index = *(int *)lpParameter ;	int i = 1; 	MYSQL *sql = psql->GetConnect();	string stemp = "insert into actor( actor_id , first_name , last_name,last_update )values(/"";	string strsql;	char str[10];	if ( psql->SelectDB(sql , "sakila") )	{			while ( i != 100 )		{			sprintf( str , "%d" , i+index );			strsql = stemp ;			strsql +=  str;			strsql += "/",/"0/",/"0/",/"0/")";			if(!sql)				return 0;			if(!psql->Query(  sql ,strsql.c_str()  ))			{				cout<<"add false"<<endl;			}			++i;		}		psql->RelConnect(sql);	}	return 0;}

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