javascript - Nodejs Mongoose Saving model undefined is not a function -

i work nodejs express routes , mongoose persist data. did core routes crud operations no problem. however, when try perform operations on 1 of fields of model , try save model model.save says .save() method: "undefined not function"

so, here's code. snippet number (1) works fine:

router.put('/:myid', function (req, res, next) { var ourupdatedata = req.body; model.findone({myid: req.params.myid.tostring()}, function (err, foundmodel) {     if (err) throw err;      if (ourupdatedata.fielda) foundmodel.fielda = ourupdatedata.fielda;     if (ourupdatedata.fieldb) foundmodel.fieldb = ourupdatedata.fieldb;     if (ourupdatedata.fieldc) foundmodel.fieldc = ourupdatedata.fieldc;     if (ourupdatedata.fieldd) foundmodel.fieldd = ourupdatedata.fieldd;     if (typeof ourupdatedata.fieldarray === "object") ourupdatedata.fieldarray = ourupdatedata.fieldarray;      foundmodel.save(function (err, updatedmodel) {         if (err) throw err;         res.send(updatedmodel);     }); }); 

});

so model has 6 fields: fielda,..b,..c,..d, myid identify index , 1 field array of values fieldarray. example above saves model, works fine. if try array field fieldarray , save model throws me "undefined not function" when use model.save() . snippet (2) code produces error:

    router.get('/:myid/:addthistofieldarray', function(req, res, next) {     var myid = req.params.myid;     var addthistofieldarray = req.params.addthistofieldarray;     model.find({myid: myid}, function (err, model) {         if (err) throw err;         var fieldarray = model.fieldarray;         fieldarray.push("new thing fieldarray");         var newfieldarray = fieldarray;         if (typeof newfieldarray === "object") model.fieldarray = newfieldarray;         model.save(function (err, updatedmodel){             if (err) throw err;             res.send(updatedmodel);         });     }); }); 

so thing above throws "undefined not function" on using model.save(.. )

i tried second variant of snippet (2), let's call snippet (3), incorporating .exec() doesn't work, throws same "undefined not function" on model.save(.. ) snippet (3) this:

    router.get('/:myid/:addthistofieldarray', function(req, res, next) {     var myid = req.params.myid;     var addthistofieldarray = req.params.addthistofieldarray;     model.find({myid: myid}).exec(function (err, model) {         if (err) throw err;         var fieldarray = model.fieldarray;         fieldarray.push("new thing fieldarray");         var newfieldarray = fieldarray;         if (typeof newfieldarray === "object") model.fieldarray = newfieldarray;         model.save(function (err, updatedmodel){             if (err) throw err;             res.send(updatedmodel);         });     }); }); 

i'll greatful inputs , suggestions!

ansering attempt of willson:

yeah, know when call model.find(.. gives array, if call model.findone(.. gives 1 object json

i tried simplify example , in version actualy did use the: "model[0].fieldarray = newfieldarray" thing array fist (the array itself) , assign new value.

the problem still persists, gives me on model.save(.. "undefined not function " )

the current code is:

    router.get('/:myid/:addthistofieldarray', function(req, res, next) {     var myid = req.params.myid;     var addthistofieldarray = req.params.addthistofieldarray;     model.find({myid: myid}).exec(function (err, model) {         if (err) throw err;         var fieldarray = model[0].fieldarray;         fieldarray.push("new thing fieldarray");         var newfieldarray = fieldarray;         if (typeof newfieldarray === "object") model[0].fieldarray = newfieldarray;         model.save(function (err, updatedmodel){             if (err) throw err;             res.send(updatedmodel);         });     }); }); 

this snippet (4) above gives on model.save(.. "undefined not function"

when use in mongoose find method, return array since discover 1 or many documents, in example querying 1 specific element id, should grab first element on returned array:

      model.find({myid: myid}).exec(function (err, documents) {             var model = documents[0];              if (err) throw err;             var fieldarray = model[0].fieldarray; 

---

here example:

var mongoose = require('mongoose'); var schema = mongoose.schema;  mongoose.connect('mongodb://localhost:27017/java-jedi');  var hackerschema = new schema({   name: string,   languages: [string] });  var hacker = mongoose.model('hacker', hackerschema);   // instantiating model. var onehacker = new hacker(); onehacker.name = 'richard stallman';  onehacker.save(function(err) {   if (err) throw err;    // finding document intentionally example   hacker.find({_id: onehacker._id}, function(err, hackers) {     var hacker = hackers[0];      // modifying document , updating it.     hacker.languages.push('lisp');     hacker.save(function(err) {       if (err) throw err;        console.log(hacker);     });   });  });