头文件
#pragma once
#include<mysql.h>
#include<iostream>
#include<string>
class MysqlConn
{
public:
//初始化数据库连接
MysqlConn();
//释放数据库连接
~MysqlConn();
//连接数据库
bool connect(std::string user, std::string password, std::string dbName, std::string ip, unsigned short port = 3306);
//更新数据库insert update delete
bool update(std::string sql);
//查询数据库
bool query(std::string sql);
//遍历结果集
bool next();
//得到结果集中的字段值
std::string value(int index);
//事务操作
bool transaction();
//提交事务
bool commit();
//事务回滚
bool rollback();
private:
void freeResult();
MYSQL* m_conn = nullptr;
MYSQL_RES* m_result = nullptr;
MYSQL_ROW m_row = nullptr;
};
cpp文件
#include "MysqlConn.h"
MysqlConn::MysqlConn()
{
m_conn = mysql_init(nullptr);
//使用编码
mysql_set_character_set(m_conn, "utf8");
}
MysqlConn::~MysqlConn()
{
if (m_conn != nullptr)
{
mysql_close(m_conn);
}
freeResult();
}
bool MysqlConn::connect(std::string user, std::string password, std::string dbName, std::string ip, unsigned short port = 3306)
{
MYSQL* ptr= mysql_real_connect(m_conn, ip.c_str(), user.c_str(), password.c_str(), dbName.c_str(), port, nullptr, 0);
return ptr!=nullptr;
}
bool MysqlConn::update(std::string sql)
{
if (mysql_query(m_conn, sql.c_str()))
{
return false;
}
return true;
}
bool MysqlConn::query(std::string sql)
{
freeResult();
if (mysql_query(m_conn, sql.c_str()))
{
return false;
}
m_result=mysql_store_result(m_conn);
return true;
}
bool MysqlConn::next()
{
if (m_result != nullptr)
{
m_row=mysql_fetch_row(m_result);
}
return false;
}
std::string MysqlConn::value(int index)
{
int columnNum = mysql_num_fields(m_result);
if (index >= columnNum || index < 0)
{
return std::string();
}
char* val = m_row[index];
unsigned long length=mysql_fetch_lengths(m_result)[index];
return std::string(val,length);
}
bool MysqlConn::transaction()
{
return mysql_autocommit(m_conn, false);
}
bool MysqlConn::commit()
{
return mysql_commit(m_conn);
}
bool MysqlConn::rollback()
{
return mysql_rollback(m_conn);
}
void MysqlConn::freeResult()
{
if (m_result)
{
mysql_free_result(m_result);
m_result = nullptr;
}
}