I'm going to build a server, and i have a list containing a struct("_id" is in it), now i want to compare the _id between the exist one in mongodb and the one in instruct.
I've finished the code, and when it comes to compiling, there are two same errors occured:
/usr/local/include/bsoncxx/v_noabi/bsoncxx/builder/stream/value_context.hpp:70:9: error: no matching function for call to ‘bsoncxx::v_noabi::builder::core::append(bsoncxx::v_noabi::document::element)’
_core->append(std::forward<T>(t));
^
where the original code are:
#include <iostream>
2 #include <cstdint>
3 #include <mongocxx/instance.hpp>
4 #include <mongocxx/client.hpp>
5 #include <mongocxx/options/find.hpp>
6 #include <mongocxx/stdx.hpp>
7
8 #include <bsoncxx/builder/basic/array.hpp>
9 #include <bsoncxx/builder/stream/document.hpp>
10 #include <bsoncxx/json.hpp>
11 #include <bsoncxx/types.hpp>
12
13
14 #include "DataStruct.h"
15 using bsoncxx::types::value;
16 using bsoncxx::builder::stream::finalize;
17 using bsoncxx::builder::stream::document;
18 using bsoncxx::builder::stream::open_document;
19 using bsoncxx::builder::stream::close_document;
20
21 int main(int, char**)
22 {
23 mongocxx::instance inst{};
24 mongocxx::client conn{mongocxx::uri{"mongodb://172.16.103.100:27017"}};
25
26
27 std::string m_Which_Attendance;
28
29 LIST_Attendance lstInfo;
30 LIST_Attendance::iterator iter;
31
32
33 for(iter = lstInfo.begin(); iter != lstInfo.end(); ++iter)
34 {
35 char datepick [10];
36 strcpy(datepick,(*iter).date.c_str());
37 int m_Mouth = (datepick[5]-48)*10+datepick[6]-48; //char to int -48
38 int m_Date = (datepick[8]-48)*10+datepick[9]-48;
39
40 if( m_Date <16 ) //find attendance_date <16 to _1
41 {
42 m_Which_Attendance = "kg_attendance_"+std::to_string(m_Mouth)+"_1";
43 }
44 else
45 {
46 m_Which_Attendance = "kg_attendance_"+std::to_string(m_Mouth)+"_2";
47
48 }
49
50
51
52
53 auto db = conn["myattendance"];
54 auto cursor = db[m_Which_Attendance].find({});
55 {
56 for(auto&& doc : cursor)
57 {
58 if( (*iter)._id == doc["_id"].get_oid().value.to_string() ) //delete same id which was exist
59 {
60
61 auto filter_builder = bsoncxx::builder::stream::document{};
62 bsoncxx::document::value filter_value = filter_builder
63 <<"_id" << doc["_id"] << bsoncxx::builder::stream::finalize;
64 db[m_Which_Attendance].delete_one(filter_value.view());
65
66
67 }
68
69 /*
70 auto builder = bsoncxx::builder::stream::document {};
71 bsoncxx::document::value doc_value = builder
72 << "_id" << (*iter)._id
73 << "name" << (*iter).name
74 << "owner" << (*iter).owner_id
75 << "owner_type" << (*iter).owner_type
76 << "status" << (*iter).status
77 << "date" << (*iter).date
78 << "relationship" << (*iter).relationship
79 << "guardian_id" << (*iter).guardian_id
80 << "school_id" << (*iter).school_id
81 << "dep_id" << (*iter).dep_id
82 << "dep_code" << (*iter).dep_code
83 << "grade_code" << (*iter).grade_code
84 << "signin_time" << (*iter).signin_time
85 << "signout_time" << (*iter).signout_time
86 << "signin_score" << (*iter).signin_score
87 << "signout_score" << (*iter).signout_score
88 << "signin_image_name" << (*iter).signin_image_name
89 << "signout_image_name" << (*iter).signout_image_name
90 << bsoncxx::builder::stream::finalize;
91
92 bsoncxx::stdx::optional<mongocxx::result::insert_one> result =
93 db[m_Which_Attendance].insert_one( std::move(doc_value) );
94 */
95 }
96 }
97
98
99 }
100
101 }
can someone help pls~
The compilation error is caused by doc["_id"] when you're building the document:
62 bsoncxx::document::value filter_value = filter_builder
63 <<"_id" << doc["_id"] << bsoncxx::builder::stream::finalize;
doc["_id"] is a bsoncxx::v_noabi::document::element but you need to build it using a bsoncxx::oid since the _id is a MongoDB ObjectId type.
With your current code, you can try with the following:
auto filter_builder = bsoncxx::builder::stream::document{};
bsoncxx::document::value filter_value = filter_builder
<< "_id"
<< bsoncxx::oid{ doc["_id"].get_oid().value.to_string() } // <- This is the change
<< bsoncxx::builder::stream::finalize;
db[m_Which_Attendance].delete_one(filter_value.view());
But looking at what you want to do, it seems that the find_one_and_delete might work for you better.
Instead of retrieving all documents (line 54) and looping on all docs trying to find the one with the matching _id, just perform the find_one_and_delete operation using the _id as shown above. Here's an example from mongocxx repository.