Mongoose Find query meaning wrong point

A problem that can be easily encountered when querying all the results of a document using Mongoose Articlecontents.getall = function (name, callback) {          var query = {};          if (name) {              query.name = name;          }   Articlecontentsmodel.find (///four parameters, where the second cannot be omitted (the second parameter is the result set to query out which document structure is included)       Query,null,       {           sort:{time:-1}       },       function (err, docs) {           if (err) {               return callback (ERR);           }           Callback (null, Docs);       });};/ /can also be written in the following form (Requier (' MongoDB ') Mymodel.find ({}). Sort ({' _id ': -1}). Limit (6). EXEC (function (Err,docs) {})

　　

Mongoose Find query meaning wrong point