mysql c 简单工具类

拼搏现实的明天。 2023-07-23 12:56 40阅读 0赞

### mysql c 简单工具类 ###

*  mysqltools.h

#pragma once
    
    #include <mysql.h>
    #include <iostream>
    #include <string>
    #include <map>
    
    using namespace std;
    
    class MySqlTools
    {
    public:
        MySqlTools(string ip, string usern, string passw, string database, int port);
        ~MySqlTools();
    
    	map<int, map<int, string>> Query(std::string query_sql_string);
    	int Exec(string exSqlStr);
    
    private:
        MYSQL conn;
    	int num_fields;
    	map<int, map<int, string>> mapsql;
    	map<int, string> mapone;
    };
    
    MySqlTools::MySqlTools(string ip,string usern,string passw,string database,int port)
    {
        mysql_init(&conn);
    	num_fields = 0;
    
        if (mysql_real_connect(&conn, ip.c_str(), usern.c_str(), passw.c_str(), database.c_str(), port, NULL, CLIENT_FOUND_ROWS))
        {
            printf("connect success!\n");
        }
    }
    
    MySqlTools::~MySqlTools()
    {
        mysql_close(&conn);
    }
    
    map<int, map<int, string>> MySqlTools::Query(std::string query_sql_string) {
    	const char* query_buffer = query_sql_string.c_str();
    	if (mysql_query(&conn, query_buffer))
    	{
    		printf("Query failed(%s)\n", mysql_error(&conn));
    	}
    	else
    	{
    		num_fields = 0;
    		mapsql.clear();
    		mapone.clear();
    
    		printf("Query success\n");
    		MYSQL_RES*  res = mysql_store_result(&conn);
    		num_fields = mysql_num_fields(res);
    		printf_s("num_fields: %d\n", num_fields);
    		MYSQL_ROW row;
    		
    		int i = 0;
    		while ((row = mysql_fetch_row(res)) != NULL)
    		{
    			int i2 = 0;
    			while (i2 <= num_fields)
    			{
    				mapone[i2] = row[i2];
    
    				i2++;
    			}
    			mapsql[i] = mapone;
    			i++;
    		}
    
    		/*map<int, map<int, string>>::iterator iter;
    		for (iter = mapsql.begin(); iter != mapsql.end(); iter++)
    		{ 
    			std::cout << iter->second[0] << "  " << iter->second[1] << std::endl;
    		}*/
    
    		mysql_free_result(res);    //释放内存    
    		delete row;
    		return mapsql;
    	}
    }
    
    int MySqlTools::Exec(string exSqlStr)
    {
    	int res = mysql_query(&conn, exSqlStr.c_str());
    	if (res)
    	{
    		printf("error\n");
    	}
    	else
    	{
    		printf("OK\n");
    	}
    	return res;
    }

*  main.cpp

#include "mysqltools.h"
    
    int main()
    {
    	MySqlTools sqldb("127.0.0.1", "root", "123456", "test", 3306);
    
    	map<int, map<int, string>> mapsql = sqldb.Query("SELECT * FROM `t2`");
    
    	map<int, map<int, string>>::iterator iter;
    	for (iter = mapsql.begin(); iter != mapsql.end(); iter++)
    	{
    		std::cout << iter->second[0] << "  " << iter->second[1] << std::endl;
    	}
    
    	map<int, map<int, string>> mapsql2 = sqldb.Query("SELECT * FROM `t1`");
    	for (iter = mapsql2.begin(); iter != mapsql2.end(); iter++)
    	{
    		std::cout << iter->second[0] << "  " << iter->second[1] << std::endl;
    	}
    
    	sqldb.Exec("UPDATE `position` SET fee = 0");
    	return 0;
    }

*  数据库
 *  ![在这里插入图片描述][20200408001621588.png]

[20200408001621588.png]: /images/20230528/ccde4fdc5f96400f84533099bab1f92b.png