Javascript Mongoose with mongodb 如何返回刚刚保存的对象？
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Mongoose with mongodb how to return just saved object?
提问by Derek
I'm new to mongoose/mongodb
我是猫鼬/mongodb 的新手
Say I'm saving something:
说我正在保存一些东西：
var instance = new TestingModel();
instance.test = 'blah2';
instance.save();
So when I save that the instance obj in the db will have, _id and test. But the _id attribute is added to the object only after entering the db. Note: I don't want to give it an id before. However, I want to grab the object in the db because I need to use the _id value, but I don't want to query it again. Is there a way where you save the object in the database and auto returns the database object so you can get the _id value?
因此，当我保存数据库中的实例 obj 时， _id 和 test. 但是_id属性只有在进入db之后才会被添加到对象中。注意：我之前不想给它一个id。但是，我想抓取db中的对象，因为我需要使用_id值，但我不想再次查询它。有没有办法将对象保存在数据库中并自动返回数据库对象，以便获得 _id 值？
回答by Ricardo Tomasi
The _idshould be present after saving:
本_id应在保存后存在：
var instance = new TestingModel()
instance.test = 'blah'
instance.save(function(err){
console.log(instance._id) // => 4e7819d26f29f407b0...
})
edit: actually the _idis set on instantiation, so it should already be there before save:
编辑：实际上_id是在实例化时设置的，因此在保存之前它应该已经存在：
var instance = new TestingModel()
console.log(instance._id) // => 4e7819d26f29f407b0...
回答by sh977218
The correct way to check is the callback of save :
正确的检查方法是 save 的回调：
instance.save(function(err,savedObj){
// some error occurs during save
if(err) throw err;
// for some reason no saved obj return
else if(!savedObj) throw new Error("no object found")
else console.log(savedObj);
})
回答by user3444748
router.post('/', function(req, res) {
var user = new User();
user.name = req.body.name;
user.token = req.body.token;
user.save(function(err, obj) {
if (err)
res.send(err);
res.json({ message: 'User created!', data: obj });
});
});
