遍历mongocxx查询以获取每个键和值

#include <bsoncxx/builder/stream/document.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>

using bsoncxx::builder::stream::document;
using bsoncxx::builder::stream::finalize;

int main() {
    // 初始化mongocxx库
    mongocxx::instance inst;

    // 连接到MongoDB数据库
    mongocxx::client client{mongocxx::uri{}};

    // 获取数据库和集合对象
    mongocxx::database db = client["mydb"];
    mongocxx::collection collection = db["mycollection"];

    // 创建查询条件
    document query_builder{};
    query_builder.append(kvp("key", "value"));

    // 执行查询
    mongocxx::cursor cursor = collection.find(query_builder.view());

    // 遍历查询结果
    for (auto&& doc : cursor) {
        // 获取文档的键和值
        for (auto&& element : doc.view()) {
            std::cout << "Key: " << element.key() << std::endl;
            std::cout << "Value: " << element.get_value() << std::endl;
        }
    }

    return 0;
}