db.cpp

linux下实现对mysql数据库的连接及相关的插入、删除和查找工作。

#include "db.h"
#include <iostream>
using namespace std;

DB::DB()
{
	
};
DB::DB(char *host,char *user,char *pass,char *database)
{
	this->host=host;
	this->user=user;
	this->pass=pass;
	this->database=database;
};
bool DB::connect(std::string charset)
{	
	mysql = mysql_init(NULL);
    if(mysql == NULL)
		return false;
    if(mysql_options(mysql,MYSQL_SET_CHARSET_NAME,"GBK"))
		return false;
	if(!mysql_real_connect(mysql, host, user, pass, database, 0, NULL, 0))
		return false;
	return true;
};
bool DB::close()
{
	mysql_close(mysql); 
	return true;
};

MYSQL_RES* DB::select(string sql)
{
	MYSQL_RES *m_res=0;
	if(mysql_query(mysql,sql.c_str()) != 0)
		return m_res;
	m_res = mysql_store_result(mysql);
	return m_res;
};
bool DB::update(std::string sql)
{
	if(mysql_query(mysql,sql.c_str()) != 0)
	{
		unsigned int error=mysql_errno(mysql);
		cout<<"mysql error"<<error<<endl;
		return false;
	}
	else 
		return true;
};
bool DB::find_code(string code)
{
	string sql="select name from general_info where code="+code;
	MYSQL_RES *m_res=0;
	if(mysql_query(mysql,sql.c_str()) != 0)
		exit(1);
	m_res = mysql_store_result(mysql);
    if(m_res==NULL)
		exit(1);
	unsigned int num_fields;
	num_fields = mysql_num_rows(m_res);
	mysql_free_result(m_res);
	if(num_fields==0)
		return false;
	else
		return true;
	
}