mysql to mongodb database and query conversion

In MongoDb you have to take the concept more general and include all the relation in it.

Your database Mysql, looks like this on mongodb:

     degree{
            _id : ...,
            name : ...,
            branches :[ {
                         _id: ...
                         name: ....,
                         syllabus : [ {
                                       _id: ...,
                                       name: ....,
                                       sort_note: ....
                                       attachment:...
                                       semetster,... 
                                      } , ..   ],...{
                       } ],
             subjects: [ {
                          _id: ..,
                          name: ....,
                          code: .....,
                          semester: ....
                       }, ...]
             }

If id_branch and id_degree are uniques like a contraint is an object else is an array.

Regards