1、在LXMysql.h和LXMysql.cpp分别定义和编写关于pin语句的代码

//获取更新数据的sql语句 where语句中用户要包含where 更新std::string GetUpdatesql(XDATA kv, std::string table, std::string where);

std::string LXMysql::GetUpdatesql(XDATA kv, std::string table, std::string where){string sql = "";if (kv.empty() || table.empty()){return "";}//update t_vedio set name= 'update001', size=1000 where id =10;sql = "update `";sql += table;sql += "` set ";for (auto ptr = kv.begin(); ptr != kv.end();ptr++){sql += "`";sql += ptr->first;sql += "`=' ";sql += ptr->second.data;sql += "',";}//去除多余的逗号sql[sql.size() - 1] = ' ';sql += " ";sql += where;return sql;}

2、编写update代码

//返回更新数量，失败返回-1int Update(XDATA kv, std::string table, std::string where);

int LXMysql::Update(XDATA kv, std::string table, std::string where){if (!mysql){return -1;}string sql = GetUpdatesql(kv, table, where);if (sql.empty()){return -1;}if (!Query(sql.c_str())){return -1;}return mysql_affected_rows(mysql);}

3、测试

    //更新数据//修改id=2的数据XDATA udata;udata["name"] = "update002";cout << " my.Update=" << my.Update(udata, "t_vedio", "where id=2") << endl;