使用C++11和相关驱动访问MongoDb
#include <cstdio>
#include <iostream>
#include <bsoncxx/array/view.hpp>
#include <bsoncxx/builder/stream/document.hpp>
#include <bsoncxx/json.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
using namespace std;
using bsoncxx::builder::stream::document;
using bsoncxx::builder::stream::finalize;
int main()
{
mongocxx::instance inst{};
mongocxx::client conn{ mongocxx::uri{} };
auto collection = conn["DbName"]["CollectionName"];
auto result = collection.find_one(document{} << "_id" << "Id" << finalize);
auto doc = *result;
auto view = doc.view();
//似乎一个view只能一次使用view["abc"]
//否则会crash
//auto enableView = view["Enable"];
//auto enable = enableView.get_bool().value;
auto accountsView = view["Accounts"];
auto accounts = accountsView.get_array().value;
for (auto acc : accounts)
{
auto v = acc.get_value();
auto tp = v.type();
if (tp == bsoncxx::type::k_utf8)
{
auto str = v.get_utf8().value.to_string();
cout << str << endl;
}
}
return 0;
}
事例中包含了读取Document中string[]的代码
其中使用for( auto acc : accounts ) 的迭代方法