mongo-cxx-driver的简单封装。

代码在：https://github.com/xyz347/mongoxclient

受Golang启发写的，可以像golang一样直接操作结构体。只有基本接口，还不是很完备。

范例：（里面很多代码是用来初始化结构体的，和封装没关系，封装的接口后面加了注释方便区分）

#include <iostream>

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

#include "mongoxclient.hpp"

mongocxx::instance instance{};

using namespace std;

struct User {
    int uid;
    string name;
    int age;
    vector<string> tags;
    vector<vector<int>> test;
    XTOSTRUCT(A(uid, "bson:_id"), O(name, age, tags, test));
};

int main(int argc, char *argv[]) {
    mongocxx::uri uri("mongodb://test:test@127.0.0.1:27018/test");
    mongocxx::client client(uri);
    mongocxx::collection collect = client["test"]["test"];

    mongoxc::Collection col(collect); // 初始化一个Collection
   
    col.RemoveAll({});  // 删除所有的document

    User u1;
    u1.uid = 123;
    u1.name = "Hello";
    u1.age = 20;
    u1.tags.push_back("study");
    u1.tags.push_back("play game");
    u1.test.resize(2);
    u1.test[0].push_back(1);
    u1.test[0].push_back(2);
    u1.test[0].push_back(3);
    u1.test[1].push_back(4);
    u1.test[1].push_back(5);
    col.Upsert(u1.uid, u1);   // 插入document
    
    u1.uid = 456;
    u1.name = "Good";
    u1.age = 22;
    u1.tags[0] = "windows";
    u1.tags[1] = "linux";
    u1.test.clear();
    u1.test.resize(2);
    u1.test[0].push_back(10);
    u1.test[0].push_back(20);
    u1.test[0].push_back(30);
    u1.test[1].push_back(40);
    u1.test[1].push_back(50);
    col.Upsert(u1.uid, u1);   // 插入document 

    u1.uid = 789;
    u1.name = "insert";
    col.Insert(u1);           // insert struct

    col.Insert(bb::vp{{"_id",1111}, {"name", "insert_bb"}}); // insert bb::vp

    cout<<"======count=="<<endl;
    cout<<col.Count()<<endl;  // Count all
    cout<<col.Find({{"_id",123}}).Count()<<endl; // Count query
    
    cout<<"======get====="<<endl;
    User get;
    User getid;
    vector<User> all;
    col.Find({{"_id",123}}).One(get); // Find
    cout<<x2struct::X::tojson(get)<<endl;
    col.FindId(456).One(getid); // Find by ID
    cout<<x2struct::X::tojson(getid)<<endl;
    col.Find({}).All(all); // Find ALL
    for (size_t i=0; i<all.size(); i++) {
        cout<<x2struct::X::tojson(all[i])<<endl;
    }

    cout<<"===skip==="<<endl;
    all.clear();
    col.Find({}).Skip(1).All(all); // Skip
    for (size_t i=0; i<all.size(); i++) {
        cout<<x2struct::X::tojson(all[i])<<endl;
    }

    cout<<"===sort==="<<endl;
    all.clear();
    col.Find({}).Sort({{"_id",-1}}).All(all); // Sort
    for (size_t i=0; i<all.size(); i++) {
        cout<<x2struct::X::tojson(all[i])<<endl;
    }

    cout<<"===projection==="<<endl;
    all.clear();
    col.Find({}).Projection({{"name",1}}).All(all); // Projection
    for (size_t i=0; i<all.size(); i++) {
        cout<<x2struct::X::tojson(all[i])<<endl;
    }

    cout<<"===update all==="<<endl;
    col.UpdateAll({}, {{"$set", bb::vp{{"name", "haha"}}}});
    all.clear();
    col.Find({}).All(all);
    for (size_t i=0; i<all.size(); i++) {
        cout<<x2struct::X::tojson(all[i])<<endl;
    }

    cout<<"=====remove====="<<endl;
    col.Remove({{"_id",bb::vp{{"$lt", 124}}}});
    cout<<col.Count()<<endl;

    return 0;
}

运行结果：

======count==
4
1
======get=====
{"uid":123,"name":"Hello","age":20,"tags":["study","play game"],"test":[[1,2,3],[4,5]]}
{"uid":456,"name":"Good","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":123,"name":"Hello","age":20,"tags":["study","play game"],"test":[[1,2,3],[4,5]]}
{"uid":456,"name":"Good","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":789,"name":"insert","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":1111,"name":"insert_bb","age":22,"tags":[],"test":[]}
===skip===
{"uid":456,"name":"Good","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":789,"name":"insert","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":1111,"name":"insert_bb","age":22,"tags":[],"test":[]}
===sort===
{"uid":1111,"name":"insert_bb","age":2,"tags":[],"test":[]}
{"uid":789,"name":"insert","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":456,"name":"Good","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":123,"name":"Hello","age":20,"tags":["study","play game"],"test":[[1,2,3],[4,5]]}
===projection===
{"uid":123,"name":"Hello","age":2,"tags":[],"test":[]}
{"uid":456,"name":"Good","age":2,"tags":[],"test":[]}
{"uid":789,"name":"insert","age":2,"tags":[],"test":[]}
{"uid":1111,"name":"insert_bb","age":2,"tags":[],"test":[]}
===update all===
{"uid":123,"name":"haha","age":20,"tags":["study","play game"],"test":[[1,2,3],[4,5]]}
{"uid":456,"name":"haha","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":789,"name":"haha","age":22,"tags":["windows","linux"],"test":[[10,20,30],[40,50]]}
{"uid":1111,"name":"haha","age":22,"tags":[],"test":[]}
=====remove=====
3