c++实现数据库的连接以及对应的增删改查功能

#include "UserManager.h" using namespace std; UserManager::UserManager() { con = mysql_init(NULL); //设置字符编码 mysql_options(con, MYSQL_SET_CHARSET_NAME, "GBK"); if (!mysql_real_connect(con, host, user, pw, database_name, port, NULL, 0)) { std::cout << "Failed to connect with database"; exit(1); } } UserManager::~UserManager() { mysql_close(con); } bool UserManager::insert_user(User& user) { char sql[8192]; sprintf_s(sql, "insert into user(id,username,password) values (%d,'%s',%d)", user.id, user.username.data(), user.password); if (mysql_query(con, sql)) { fprintf(stderr, "Failed to insert data,Error:%s\n", mysql_error(con)); return false; } return true; } bool UserManager::delete_user(User& user) { char sql[8192]; sprintf_s(sql, " DELETE FROM user WHERE id=%d", user.id); if (mysql_query(con, sql)) { fprintf(stderr, "Failed to delete data,Error:%s\n", mysql_error(con)); return false; } return true; } bool UserManager::update_user(User& user) { char sql[8192]; sprintf_s(sql, " UPDATE user SET username='%s',password=%d WHERE id=%d", user.username.data(), user.password,user.id); if (mysql_query(con, sql)) { fprintf(stderr, "Failed to updata data,Error:%s\n", mysql_error(con)); return false; } return true; } vector<User> UserManager::query_user(string condition) { vector<User> userList; char sql[8192]; sprintf(sql, " SELECT * FROM user %s",condition.c_str()); if (mysql_query(con, sql)) { fprintf(stderr, "Failed to select data,Error:%s\n", mysql_error(con)); return {}; } MYSQL_RES* res = mysql_store_result(con); MYSQL_ROW row; while ((row = mysql_fetch_row(res))) { User user; user.id = atoi(row[0]); user.username = atoi(row[1]); user.password = atoi(row[2]); userList.push_back(user); } for (int i = 0; i < userList.size(); i++) { cout << userList[i].id << "," << userList[i].username << "," << userList[i].password << endl; } return userList; }