c++连接mongocxx,将代码进行类封装
这里需要注意一个事情,就是instance必须变成全局类
static mongocxx::instance instance{}; //这里一定要注意
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#ifndef GET_DATA_HPP #define GET_DATA_HPP #include <iostream> #include <string> #include <vector> #include "conf.hpp" #include <nlohmann/json.hpp> using json = nlohmann::json; #include <mongocxx/client.hpp> #include <mongocxx/instance.hpp> #include <mongocxx/uri.hpp> #include <bsoncxx/builder/stream/document.hpp> #include <bsoncxx/json.hpp> #include <bsoncxx/types.hpp> #include <stdio.h> using bsoncxx::builder::stream::document; using bsoncxx::builder::stream::finalize; // 实例化 mongocxx::instance 对象,必须变成全局类 static mongocxx::instance instance{}; mongocxx::client get_mongo_client() { // 先获取数据库信息,用于链接数据库用 json mongo_infor; mongo_infor = get_mongo_conf(); //std::cout << mongo_infor << std::endl; string mongo_infor_host = mongo_infor["host"]; string mongo_infor_port = mongo_infor["port"]; //std::cout << mongo_infor_host << std::endl; //std::cout << mongo_infor_port << std::endl; // "mongodb://localhost:27017" 拼接链接Mongo的字符串 string mongo_uri = "mongodb://" + mongo_infor_host + ':' + mongo_infor_port; std::cout << mongo_uri << std::endl; // 链接mongo // instance变成全局的了,要不报错 // mongocxx::instance inst{}; // 实例化 Mongocxx 库 // mongocxx::uri uri("mongodb://localhost:27017"); // 连接 MongoDB URI mongocxx::uri uri(mongo_uri); // 连接 MongoDB URI mongocxx::client client(uri); // 创建连接实例 return client; } mongocxx::database get_mongo_db(mongocxx::client& client, std::string& db_name) { // 先获取数据库信息,用于链接数据库用 json mongo_infor; mongo_infor = get_mongo_conf(); string mongo_infor_data_db = mongo_infor[db_name]; //data_base_information // std::cout << mongo_infor_data_db << std::endl; auto db = client[mongo_infor_data_db]; // 获取集合 return db; } mongocxx::collection get_mongo_collection(mongocxx::database& db_name, const std::string& collection_name) { return db_name[collection_name]; } int get_mongo_cursor(mongocxx::collection& collection) { // 获取表名,一个数据存了多少个表(因为数据量比较大,所以需要进行数据拆分) // 查询文档 // 构造查询条件 string mycolumn_name = "teacher_20230417"; auto cursor = collection.find(document{} << finalize); std::cout << "column_value" << mycolumn_name << std::endl; for (auto& doc : cursor) { auto column_value = doc["teacher_20230417"].get_utf8().value.to_string(); std::cout << column_value << std::endl; } return 0; } int get_data_infor_table() { mongocxx::client client; client = get_mongo_client(); mongocxx::database db; std::string db_name = "db_infor"; db = get_mongo_db(client, db_name); mongocxx::collection collection; std::string coll_table_name = "teacher_20230417"; coll_table_name = coll_table_name + "_table_infor"; collection = get_mongo_collection(db, coll_table_name); get_mongo_cursor(collection); return 0; } #endif // GET_DATA_HPP
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#ifndef GET_DATA_HPP #define GET_DATA_HPP #include <iostream> #include <string> #include <vector> #include "conf.hpp" #include <nlohmann/json.hpp> using json = nlohmann::json; #include <mongocxx/client.hpp> #include <mongocxx/instance.hpp> #include <mongocxx/uri.hpp> #include <bsoncxx/builder/stream/document.hpp> #include <bsoncxx/json.hpp> #include <bsoncxx/types.hpp> using bsoncxx::builder::stream::document; using bsoncxx::builder::stream::finalize; static mongocxx::instance instance{}; class MongoManager { public: MongoManager() { // 获取数据库信息,用于链接数据库用 json mongo_infor; mongo_infor = get_mongo_conf(); std::string mongo_infor_host = mongo_infor["host"]; std::string mongo_infor_port = mongo_infor["port"]; // 拼接链接Mongo的字符串 std::string mongo_uri = "mongodb://" + mongo_infor_host + ':' + mongo_infor_port; std::cout << mongo_uri << std::endl; // 链接mongo // mongocxx::instance inst{}; // 实例化 Mongocxx 库 mongocxx::uri uri(mongo_uri); // 连接 MongoDB URI client = mongocxx::client(uri); // 创建连接实例 } mongocxx::database get_database(std::string db_name) { // 先获取数据库信息,用于链接数据库用 json mongo_infor; mongo_infor = get_mongo_conf(); std::string mongo_infor_data_db = mongo_infor[db_name]; auto db = client[mongo_infor_data_db]; return db; } mongocxx::collection get_collection(mongocxx::database& db, std::string coll_name) { return db[coll_name]; } void get_cursor(mongocxx::collection& coll) { auto cursor = coll.find(document{} << finalize); for (auto&& doc : cursor) { // 获取指定列的值 auto mycolumn = doc["name"].get_utf8().value.to_string(); std::cout << "mycolumn: " << mycolumn << std::endl; } } private: mongocxx::client client; }; int get_data_infor_table() { MongoManager manager; auto db = manager.get_database("db_data"); auto coll = manager.get_collection(db, "testcollection"); manager.get_cursor(coll); return 0; } #endif // GET_DATA_HPP
作者:沐禹辰
出处:http://www.cnblogs.com/renfanzi/
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接。
出处:http://www.cnblogs.com/renfanzi/
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接。