• C++ 实战Mongodb CRUD操作基本用法

    系列数据库开发

    文章目录

    前言

    提示：以下是本篇文章正文内容，下面案例可供参考

    一、mongodb driver

    二、使用步骤

    1.数据库基本功能

    #pragma once
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using bsoncxx::builder::stream::document;
using bsoncxx::builder::stream::open_array;
using bsoncxx::builder::stream::close_array;
using bsoncxx::builder::stream::open_document;
using bsoncxx::builder::stream::close_document;
using bsoncxx::builder::stream::finalize;
using bsoncxx::builder::basic::kvp;
using bsoncxx::builder::basic::make_document;
using bsoncxx::builder::basic::make_array;


static mongocxx::pool *s_pool = nullptr;
bool mongoInit() {
  static mongocxx::instance inst{}; 
  mongocxx::uri uri{"mongodb://127.0.0.1:27017/?minPoolSize=0&maxPoolSize=100"};
  s_pool = new mongocxx::pool(uri);
  auto client = s_pool->acquire();
  return (bool)client;
}

void mongoQuit() {
  delete s_pool;
  s_pool = nullptr;
}

mongocxx::pool::entry mongoClient() { 
	return s_pool->acquire(); 
}

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    2.数据库高级操作

    CRUD

    插入数据

    mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];
auto location= (*client)["places"]["location"];
auto sites= (*client)["places"]["sites"];
auto builder = document{};

auto coordinates = bsoncxx::builder::stream::array{};
coordinates << 1 << 1;
builder<< "type"<< "Point" <<"coordinates" << coordinates;        
auto docvalue = builder << finalize;
auto doc_value = builder<< "name" << "Central Park" 
						<< "category" << "Parks"
						<< "location" << docvalue << finalize;
auto doc_value2 = builder << "name" << "MidCentral Park"
                       << "category" << "House"
                       << "count" << 1
                       << "modifydate" << open_array << "2022" << "2023" << "2024" << close_array
                       << "position" << open_document << "x" << 203 << "y" << 102 << close_document
                       << "createdate" << open_array
                       << open_document<< "year"<< 2022<< "month" << 02<< "day" << 22 << close_document
                       << open_document<< "year" << 2021<< "month" << 01<< "day" << 21 << close_document
                       << close_array
                       << finalize;

std::vector<bsoncxx::document::value> documents;
for(int i=0;i<3;i++){
     documents.push_back(document{} 
                 << "name" << "My House" 
   				 << "category" << "house"
   				 << "location" << "SH PuDong"
                 << finalize);
 }

try {
    places.insert_one(doc_value.view());
    location.insert_one(doc_value2.view());         //插入一条数据
    sites.insert_many(documents);                   //插入多条数据
} catch (const std::exception &e) {
    std::cerr << e.what() << '\n';
}
mongoQuit();

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    查询数据

    mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];
auto location= (*client)["places"]["location"];
auto builder = document{};
auto doc_value = builder<< "name" << "MidCentral Park" << finalize;
mongocxx::cursor results = places.find({});
bsoncxx::stdx::optional<bsoncxx::document::value> results2 = location.find_one(doc_value.view());
for (const bsoncxx::document::view &result: results) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}
if (results2 ){
    const bsoncxx::document::view &view = results2 ->view();
    std::cout << "location is " << view["_id"].get_oid().value.to_string()<< std::endl;
    if(view.find("modifydate") != docView.end()){
    	const bsoncxx::array::view &dates= view["modifydate"].get_array().value;
        for (bsoncxx::array::element &date: dates) {
        	std::cout<< date.get_utf8().value.to_string()<<std::endl;
        }
    }
}
//统计数量
int pagesize= 10;
int pageIndex = 0;
int64_t dwnum = location.count_documents({});        //查询数据总数
int32_t pagenumer = dwnum / pagesize;                //用于计算分页数量
//用于分页查询使用
mongocxx::options::find opts = mongocxx::options::find{};
auto order = document{} << "name" << 1 << finalize;   //name的值、升序或者降序排列
opts.sort(order.view()).skip(pageindex* pagesize).limit(pagesize);
auto filter = document{} << "category" << "Parks" << finalize;
mongocxx::cursor results3 = location.find(filter.view(), opts);
for (const bsoncxx::document::view &result: results3 ) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}

//或条件查询
auto filter2 = document{} << "$or" << open_array
                          << open_document << "name" << "Central Park" << close_document
                          << open_document << "category" << "Parks" << close_document << close_array 
                          << finalize;
mongocxx::cursor results3 = places.find(filter2.view());
for (const bsoncxx::document::view &result: results3 ) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}

auto filter3 = document{} << "name" << open_document 
						  << "$ne" << "Central Park"
						  << close_document << finalize;
mongocxx::cursor results4 = places.find(filter3.view());
for (const bsoncxx::document::view &result: results4 ) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}

//模糊查询、不区分大小写
auto filtername = "Central";
auto filter4 = open_document << "name" << open_document 
							 << "$regex" << filtername  
							 << "$options" << "i" 
							 << close_document << finalize;
mongocxx::cursor results5 = places.find(filter4 .view());
for (const bsoncxx::document::view &result: results5 ) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}

auto alarmtimebegin = 1;
auto alarmtimeend = 10;
auto filter5 = document{} << "createdate" << open_document
                    << "$gte" << timebegin << "$lt" << timeend
                    << close_document
                    << finalize;
mongocxx::cursor results6 = location.find(filter5.view());
for (const bsoncxx::document::view &result: results6 ) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}


//in 条件查询
auto deviceids[] = {1,2,3,4};
auto builder = document{};
auto ids = bsoncxx::builder::stream::array{};
for (auto deviceid : deviceids) {
    ids << deviceid;
}
auto filter6 = builder << "id" << open_document << "$in" << ids << close_document << finalize;
mongocxx::cursor results7 = location.find(filter6.view());
for (const bsoncxx::document::view &result: results7 ) {
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}

mongoQuit();

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    更新数据

    mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];
auto location= (*client)["places"]["location"];
auto builder = document{};
auto doc_value = builder << "category" << "Parks 2" << finalize;
mongocxx::options::update updopts{};
updopts.upsert(true);               //当doc不存在时,会存入数据
auto result = places.update_one(document{} << "name" << "Central Park" << finalize,
											doc_value.view(),updopts);
auto result2 = location.update_many(document{} << "count" << open_document << "$lt" << 100 << close_document << finalize);
											
if (!result) {
    std::cout<< "update failed"<<std::endl;
}
if (!result2) {
    std::cout<< "update2 failed"<<std::endl;
}
mongoQuit();

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    删除数据

    mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];
auto builder = document{};
auto doc_value = builder<< "name" << "Central Park" << "category" << "Parks" << finalize;
auto doc_value2  = document{} << "name" << open_document 
						  << "$ne" << "Central Park"
						  << close_document << finalize;
auto doc_value3 = document{} << "$or" << open_array
                          << open_document << "name" << "Central Park" << close_document
                          << open_document << "category" << "Parks" << close_document << close_array 
                          << finalize;		
auto doc_value4 = builder<< "category" << "Parks" << finalize;				  
try {
    places.delete_one(doc_value.view());
    places.delete_one(doc_value2.view());
    places.delete_one(doc_value3.view());
    places.delete_many(doc_value4.view());     //删除多个case
} catch (const std::exception &e) {
    std::cerr << e.what() << '\n';
}
mongoQuit();

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    高级操作

    多边形查询，圆形查询
    参考如下方式实现

    db.places.find({
	location:
	{$geoWithin:{          
			$geometry:{type:"Polygon",coordinates:[[[0,2],[2,2],[2,0],[0,0],[0,2]]]}
	}}
})

db.places.find({
	location:{ $near:{
			$geometry: { type: "Point",  coordinates: [ 1, 1 ] },
			$minDistance: 0,
			$maxDistance: 100000
		}
	}})

db.places.find( {
		location: { $geoWithin: { $centerSphere: [ [ 1, 1 ], (300000/1609)/3963.2 ] } }
} )

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    mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];

int coordinatedata[5][2] = {{0,2},{2,2},{2,0},{0,0},{0,2},};
auto builder = document{};
auto mutilcoordinates = bsoncxx::builder::stream::array{};
auto coordinates = bsoncxx::builder::stream::array{};
for(int i=0;i<5;i++){
	auto xy = bsoncxx::builder::stream::array{};
    xy << coordinatedata[i][0] << coordinatedata[i][1];
	coordinates<< xy;
}
mutilcoordinates<< coordinates;
builder<< "type"<< "Polygon" <<"coordinates" << mutilcoordinates;              
auto doc_value = builder << finalize;
auto results = places.find(document{} << "location" << open_document << "$geoWithin" << open_document << "$geometry" << doc_value << close_document << close_document << finalize);
for(const auto &result:results){
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}
mongoQuit();


mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];
int x = 1;
int y = 1;
auto builder = document{};
auto point = bsoncxx::builder::stream::array{};
point << x << y;
builder<< "type"<< "Point" <<"coordinates" << point;        
auto doc_value = builder << finalize;
auto results = places.find(document{} << "location" << open_document << "$near" << open_document << "$geometry" << doc_value <<  "$minDistance" << 0 << "$maxDistance" << 300000 << close_document << close_document << finalize);
for(const auto &result:results){
	std::cout<< "polygon query name: "<< result["name"].get_utf8().value.to_string() << "category: "<< result["category"].get_utf8().value.to_string() <<std::endl;
}

auto builder2 = document{};
auto point2 = bsoncxx::builder::stream::array{};
auto centersphere = bsoncxx::builder::stream::array{};
point2 << x << y;
centersphere << point2;
centersphere << (300000/1609)/3963.2;	
builder2 << "location" << open_document << "$geoWithin" << open_document << "$centerSphere" << centersphere << close_document << close_document;   
auto doc_value2 = builder2 << finalize;
auto results4 = places.find(doc_value2.view());
for(const auto &result:results4){
	std::cout<< "circle2 query name: "<< result["name"].get_utf8().value.to_string() <<std::endl;
}
mongoQuit();


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    聚合操作
    参考如下方式实现

    db.getCollection('runoob').aggregate(
    {"$match":{"date": {'$gte':1667232000,'$lt':1667923200},"url":"http://www.runoob.com"}}
	,{"$group": {
        "_id": { "$subtract": [
				{ "$subtract": [ "$date",  1667232000] },
                { "$mod": [{ "$subtract": [ "$date", 1667232000 ] },3600]}
			]},		
        "total": {'$sum': 1}
    }}
    ,{"$project": {
            "_id": 1,
            "count":1,
            'datetime': {'$add': [1667232000, '$_id']}                  
    }}
	,{"$sort": {
        'datetime': 1
    }}	
)

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    mongoInit();
auto client=mongoClient();
auto places = (*client)["places"]["places"];
long fromdate=1667232000;
long enddate= 1667923200;
std::string url = "http://www.runoob.com";
auto filter = document{}<< "url" << url << "dt" << open_document << "$gte" << fromdate << "$lt" << enddate << close_document<< finalize;
mongocxx::pipeline pipelineInst;
pipelineInst.match(filter.view())
            .group(make_document(kvp("_id", 
                make_document(kvp("$subtract", make_array( make_document(kvp("$subtract", make_array("$dt", fromdate))), 
                make_document(kvp("$mod", make_array(make_document(kvp("$subtract", make_array("$dt", fromdate))) , statisticunit())))
                    )))   ), 
                kvp("count", make_document(kvp("$sum", 1)))
                ))
            .project(make_document(kvp("_id", 1),kvp("count",1),kvp("datetime", 
            make_document(kvp("$add", make_array(fromdate, "$_id"))))
            ));

int total = 0;    
int topVal = 0;                      
for (const auto& result_place : result_places) {
    int64_t count = result_place["count"].get_int32().value;
    int64_t id = result_place["_id"].get_int64().value;
    total += count;
    if(count> topVal) 
        topVal = count;
}
std::cout<< "total: "<< total  << " topVal:"<< topVal <<std::endl;
mongoQuit();

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    总结

    本文介绍了一些常用c++ mongo driver之crud的用法与高级用法，希望对你有所帮助。

    老铁：如果觉得还不错，别忘了随手点赞转发+关注哦！

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  • 原文地址：https://blog.csdn.net/weixin_44834554/article/details/127057842