Esercizi Lettura MongoDB C++
- Esercizio 1: Lettura di un singolo documento usando mongocxx (metodo sequenziale)
- Esercizio 2: Lettura di più documenti usando mongocxx (metodo sequenziale)
- Esercizio 3: Lettura di un singolo documento usando mongocxx (OOP)
- Esercizio 4: Lettura di più documenti usando mongocxx (OOP)
- Esercizio 5: Lettura di un singolo documento usando mongo-c-driver (metodo sequenziale)
- Esercizio 6: Lettura di più documenti usando mongo-c-driver (metodo sequenziale)
- Esercizio 7: Lettura di un singolo documento usando mongo-c-driver (OOP)
- Esercizio 8: Lettura di più documenti usando mongo-c-driver (OOP)
Ecco degli esercizi semplici con soluzione per praticare la lettura di dati in MongoDB utilizzando C++ sia in modo sequenziale che OOP.
Esercizio 1: Lettura di un singolo documento usando mongocxx (metodo sequenziale)
Stabilire una connessione a MongoDB e leggere un singolo documento.
#include <mongocxx/client.hpp>#include <mongocxx/instance.hpp>#include <mongocxx/uri.hpp>#include <bsoncxx/json.hpp>#include <bsoncxx/builder/basic/document.hpp>#include <iostream>
int main() { mongocxx::instance instance{}; mongocxx::client client{mongocxx::uri{"mongodb://localhost:27017"}}; auto collection = client["test_db"]["test_collection"];
bsoncxx::builder::basic::document filter{}; filter.append(bsoncxx::builder::basic::kvp("name", "John Doe"));
auto result = collection.find_one(filter.view()); if (result) { std::cout << bsoncxx::to_json(*result) << std::endl; } else { std::cout << "Documento non trovato" << std::endl; }
return 0;}
Esercizio 2: Lettura di più documenti usando mongocxx (metodo sequenziale)
Stabilire una connessione a MongoDB e leggere più documenti.
#include <mongocxx/client.hpp>#include <mongocxx/instance.hpp>#include <mongocxx/uri.hpp>#include <bsoncxx/json.hpp>#include <bsoncxx/builder/basic/document.hpp>#include <iostream>
int main() { mongocxx::instance instance{}; mongocxx::client client{mongocxx::uri{"mongodb://localhost:27017"}}; auto collection = client["test_db"]["test_collection"];
bsoncxx::builder::basic::document filter{}; filter.append(bsoncxx::builder::basic::kvp("status", "active"));
auto cursor = collection.find(filter.view()); for (auto&& doc : cursor) { std::cout << bsoncxx::to_json(doc) << std::endl; }
return 0;}
Esercizio 3: Lettura di un singolo documento usando mongocxx (OOP)
Creare una classe per gestire la connessione a MongoDB e leggere un singolo documento.
#include <mongocxx/client.hpp>#include <mongocxx/instance.hpp>#include <mongocxx/uri.hpp>#include <bsoncxx/json.hpp>#include <bsoncxx/builder/basic/document.hpp>#include <iostream>
class MongoDBClient {private: mongocxx::instance instance{}; mongocxx::client client{mongocxx::uri{"mongodb://localhost:27017"}};public: MongoDBClient() = default;
void leggiDocumento(const std::string& db_name, const std::string& coll_name, const bsoncxx::document::view& filter) { auto collection = client[db_name][coll_name]; auto result = collection.find_one(filter); if (result) { std::cout << bsoncxx::to_json(*result) << std::endl; } else { std::cout << "Documento non trovato" << std::endl; } }};
int main() { MongoDBClient client; bsoncxx::builder::basic::document filter{}; filter.append(bsoncxx::builder::basic::kvp("name", "John Doe")); client.leggiDocumento("test_db", "test_collection", filter.view()); return 0;}
Esercizio 4: Lettura di più documenti usando mongocxx (OOP)
Creare una classe per gestire la connessione a MongoDB e leggere più documenti.
#include <mongocxx/client.hpp>#include <mongocxx/instance.hpp>#include <mongocxx/uri.hpp>#include <bsoncxx/json.hpp>#include <bsoncxx/builder/basic/document.hpp>#include <iostream>
class MongoDBClient {private: mongocxx::instance instance{}; mongocxx::client client{mongocxx::uri{"mongodb://localhost:27017"}};public: MongoDBClient() = default;
void leggiDocumenti(const std::string& db_name, const std::string& coll_name, const bsoncxx::document::view& filter) { auto collection = client[db_name][coll_name]; auto cursor = collection.find(filter); for (auto&& doc : cursor) { std::cout << bsoncxx::to_json(doc) << std::endl; } }};
int main() { MongoDBClient client; bsoncxx::builder::basic::document filter{}; filter.append(bsoncxx::builder::basic::kvp("status", "active")); client.leggiDocumenti("test_db", "test_collection", filter.view()); return 0;}
Esercizio 5: Lettura di un singolo documento usando mongo-c-driver (metodo sequenziale)
Stabilire una connessione a MongoDB e leggere un singolo documento usando mongo-c-driver.
#include <mongoc/mongoc.h>#include <bson/bson.h>#include <iostream>
int main() { mongoc_init();
mongoc_client_t *client = mongoc_client_new("mongodb://localhost:27017"); mongoc_collection_t *collection = mongoc_client_get_collection(client, "test_db", "test_collection");
bson_t *filter = BCON_NEW("name", BCON_UTF8("John Doe")); mongoc_cursor_t *cursor = mongoc_collection_find_with_opts(collection, filter, nullptr, nullptr);
const bson_t *doc; if (mongoc_cursor_next(cursor, &doc)) { char *str = bson_as_canonical_extended_json(doc, nullptr); std::cout << str << std::endl; bson_free(str); } else { std::cout << "Documento non trovato" << std::endl; }
bson_destroy(filter); mongoc_cursor_destroy(cursor); mongoc_collection_destroy(collection); mongoc_client_destroy(client); mongoc_cleanup();
return 0;}
Esercizio 6: Lettura di più documenti usando mongo-c-driver (metodo sequenziale)
Stabilire una connessione a MongoDB e leggere più documenti usando mongo-c-driver.
#include <mongoc/mongoc.h>#include <bson/bson.h>#include <iostream>
int main() { mongoc_init();
mongoc_client_t *client = mongoc_client_new("mongodb://localhost:27017"); mongoc_collection_t *collection = mongoc_client_get_collection(client, "test_db", "test_collection");
bson_t *filter = BCON_NEW("status", BCON_UTF8("active")); mongoc_cursor_t *cursor = mongoc_collection_find_with_opts(collection, filter, nullptr, nullptr);
const bson_t *doc; while (mongoc_cursor_next(cursor, &doc)) { char *str = bson_as_canonical_extended_json(doc, nullptr); std::cout << str << std::endl; bson_free(str); }
bson_destroy(filter); mongoc_cursor_destroy(cursor); mongoc_collection_destroy(collection); mongoc_client_destroy(client); mongoc_cleanup();
return 0;}
Esercizio 7: Lettura di un singolo documento usando mongo-c-driver (OOP)
Creare una classe per gestire la connessione a MongoDB e leggere un singolo documento usando mongo-c-driver.
#include <mongoc/mongoc.h>#include <bson/bson.h>#include <iostream>
class MongoDBClient {private: mongoc_client_t *client;public
: MongoDBClient(const std::string& uri) { mongoc_init(); client = mongoc_client_new(uri.c_str()); }
~MongoDBClient() { mongoc_client_destroy(client); mongoc_cleanup(); }
void leggiDocumento(const std::string& db_name, const std::string& coll_name, const bson_t* filter) { mongoc_collection_t *collection = mongoc_client_get_collection(client, db_name.c_str(), coll_name.c_str()); mongoc_cursor_t *cursor = mongoc_collection_find_with_opts(collection, filter, nullptr, nullptr);
const bson_t *doc; if (mongoc_cursor_next(cursor, &doc)) { char *str = bson_as_canonical_extended_json(doc, nullptr); std::cout << str << std::endl; bson_free(str); } else { std::cout << "Documento non trovato" << std::endl; }
mongoc_cursor_destroy(cursor); mongoc_collection_destroy(collection); }};
int main() { MongoDBClient client("mongodb://localhost:27017");
bson_t *filter = BCON_NEW("name", BCON_UTF8("John Doe")); client.leggiDocumento("test_db", "test_collection", filter); bson_destroy(filter);
return 0;}
Esercizio 8: Lettura di più documenti usando mongo-c-driver (OOP)
Creare una classe per gestire la connessione a MongoDB e leggere più documenti usando mongo-c-driver.
#include <mongoc/mongoc.h>#include <bson/bson.h>#include <iostream>
class MongoDBClient {private: mongoc_client_t *client;public: MongoDBClient(const std::string& uri) { mongoc_init(); client = mongoc_client_new(uri.c_str()); }
~MongoDBClient() { mongoc_client_destroy(client); mongoc_cleanup(); }
void leggiDocumenti(const std::string& db_name, const std::string& coll_name, const bson_t* filter) { mongoc_collection_t *collection = mongoc_client_get_collection(client, db_name.c_str(), coll_name.c_str()); mongoc_cursor_t *cursor = mongoc_collection_find_with_opts(collection, filter, nullptr, nullptr);
const bson_t *doc; while (mongoc_cursor_next(cursor, &doc)) { char *str = bson_as_canonical_extended_json(doc, nullptr); std::cout << str << std::endl; bson_free(str); }
mongoc_cursor_destroy(cursor); mongoc_collection_destroy(collection); }};
int main() { MongoDBClient client("mongodb://localhost:27017");
bson_t *filter = BCON_NEW("status", BCON_UTF8("active")); client.leggiDocumenti("test_db", "test_collection", filter); bson_destroy(filter);
return 0;}