Корректный, хоть и грубый захват JSON'а

src/DAO/MySQLUserDAO.cpp

@@ -23,6 +23,18 @@ optional<User> MySQLUserDAO::GetByGUID(string guid)
 
 std::optional<User> MySQLUserDAO::GetByLogin(std::string login)
 {
+  auto sql_result = session_.sql("SELECT * FROM `up_and_down`.`users` WHERE (login = '" + login +  "') LIMIT 1;"s).execute();
+  list<mysqlx::Row> rows = sql_result.fetchAll();
+
+  if (rows.size())
+  {
+    auto row_data = *rows.begin();
+
+    string replicated_login = row_data[1].get<string>();
+
+    cout << "SUCCESS!" << endl;
+  }
+
   return nullopt;
 }
 

src/endpoints_handlers/AuthRegistrationExecutor.h

@@ -33,14 +33,16 @@ public:
     auto body = req.body();
     object json_as_object = json::parse(body).as_object();
 
-    std::string login = serialize(json_as_object.at("login").as_string());
-    std::string password = serialize(json_as_object.at("password").as_string());
+    std::string login = json_as_object.at("login").as_string().c_str();
+    std::string password = json_as_object.at("password").as_string().c_str();
 
     User user;
 
     user.SetLogin(login);
     user.SetPassword(password);
 
+    user_dao_->GetByLogin(login);
+
     http::response<ResponseType> res{
         http::status::ok, req.version()
       };

src/main.cpp

@@ -45,21 +45,6 @@ int main(int argc, char* argv[])
   string mysql_credentials = argv[5];
 
   uad::SetMySqlSession(new mysqlx::Session(mysql_credentials));
-  auto& session = uad::GetMySqlSession();
-
-  auto schema = session.getSchema("up_and_down");
-
-  auto collections_names = schema.getCollectionNames();
-  auto users_collection = schema.getCollection("users");
-  auto users_collection_2 = session.sql("SELECT * FROM up_and_down.users;").execute();
-
-  auto users_rows = users_collection_2.fetchAll();
-
-  auto rows = *users_rows.begin();
-
-  const auto& user_guid = static_cast<string>(rows.get(0));
-  const auto& user_login = static_cast<string>(rows.get(1));
-  const auto& user_hashed_password = static_cast<string>(rows.get(2));
 
   net::io_context ioc{threads};