Question

Windows 7，msys2，编译器MinGW

尝试从C ++代码连接到MongoDB实例。使用下一个命令运行mongod：

mongod --dbpath ./dev-db --bind_ip 127.0.0.1 --port 27017

我通常可以通过mongo和Robomongo连接到此数据库。

对于c ++代码，我成功编译并安装了最后一个稳定的Mongo C ++驱动程序。我从官方tutorial获取的代码：

#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
#include <mongocxx/uri.hpp>

mongocxx::uri uri("mongodb://127.0.0.1:27017");
mongocxx::client conn{uri};
auto db = conn["test"];

bsoncxx::document::value restaurant_doc =
    document{} << "address" << open_document << "street"
               << "2 Avenue"
               << "zipcode"
               << "10075"
               << "building"
               << "1480"
               << "coord" << open_array << -73.9557413 << 40.7720266 << close_array
               << close_document << "borough"
               << "Manhattan"
               << "cuisine"
               << "Italian"
               << "grades" << open_array << open_document << "date"
               << bsoncxx::types::b_date{std::chrono::milliseconds{12323}} << "grade"
               << "A"
               << "score" << 11 << close_document << open_document << "date"
               << bsoncxx::types::b_date{std::chrono::milliseconds{121212}} << "grade"
               << "B"
               << "score" << 17 << close_document << close_array << "name"
               << "Vella"
               << "restaurant_id"
               << "41704620" << finalize;
auto res = db["restaurants"].insert_one(std::move(restaurant_doc))

这提供了下一个错误：

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
terminate called after throwing an instance of 'mongocxx::v_noabi::bulk_write_exception'
  what():  No suitable servers found (`serverSelectionTryOnce` set): [Failed to resolve '127.0.0.1']: generic server error

如何避免此问题并连接到数据库？

Answer 1

您的副本缺少示例的第一行：

mongocxx::instance inst{};

见http://mongodb.github.io/mongo-cxx-driver/mongocxx-v3/tutorial/#make-a-connection。 mongocxx::instance构造函数和析构函数分别初始化和关闭驱动程序，因此在使用驱动程序之前必须创建mongocxx::instance，并且只要驱动程序正在使用中，就必须保持活动状态。

Answer 2

看起来它正在尝试DNS查找127.0.0.1。尝试将其更改为localhost（将解析为相同的IP）

mongocxx::uri uri("mongodb://localhost:27017");

无法从C ++代码连接到MongoDB

2 个答案: