javascript - 在 CouchDB 中使用 Mapreduce 方法链接文档

Question

department {
               "_id": "1", 
               "department": "Computers",
               "type": "Department", 
               "room_no": "102", 
               "HOD": "Mr. G Rahul",
               "floor": "1st Floor" 
            }

student {
             "_id": "fdf370e2f43d4af1b505b8913502a5e4",
             "_rev": "1-16df9a4cd45ca69009ab6c9767425a8e",
             "student Name": "H Ravi",
             "date_of_birth": "March 1, 1993",
             "roll_no": "55",
             "inter_marks": "820",
             "secondary_marks": "420"
             "department_id": "1",
             "type": "student"
         }

map 功能

function(doc) {
              var id,department,student,hod,dob;
              if(doc.type == 'student') {
                      id = doc.department_id;
                      dob = new Date(doc.date_of_birth)
                  student = doc;    
              }
             }
       emit(dob, {'_id': id,"student_doc": student});
     }

编写 map 函数后，我们使用 URL“//localhost:5984/db_name/_design/design_name/_view/view_name”调用 View 。在该 URL 中，我们将在“view_name”之后附加 ?include_docs=true("//localhost:5984/db_name/_design/design_name/_view/view_name/?include_docs=true">)通过在emit中使用_id来获取文档，例如:emit(dob,{"_id": id})它将返回链接id的文档...我的问题是如何我们在reduce函数中访问该文档。

Answer 1

你不能，文档是在查询时获取的，而不是在索引时获取的，因此reduce函数永远不会看到该数据。抱歉!