How to exclude one particular field from a collection in Mongoose?

I have a NodeJS application with Mongoose ODM(Mongoose 3.3.1). I want to retrieve all fields except 1 from my collection.For Example: I have a collection Product Which have 6 fields,I want to select all except a field "Image" . I used "exclude" method, but got error.. This was my code.

    var Query = models.Product.find();
Query.exclude('title Image');


if (req.params.id) {
Query.where('_id', req.params.id);
}




Query.exec(function (err, product) {
if (!err) {
return res.send({ 'statusCode': 200, 'statusText': 'OK', 'data': product });
} else {
return res.send(500);
}
});

But this returns error

Express
500 TypeError: Object #<Query> has no method 'exclude'.........

Also I tried, var Query = models.Product.find().exclude('title','Image'); and var Query = models.Product.find({}).exclude('title','Image'); But getting the same error. How to exclude one/(two) particular fields from a collection in Mongoose.

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I don't know where you read about that .exclude function, because I can't find it in any documentation.

But you can exclude fields by using the second parameter of the find method.

Here is an example from the official documentation:

db.inventory.find( { type: 'food' }, { type:0 } )

This operation returns all documents where the value of the type field is food, but does not include the type field in the output.

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最佳答案

Use query.select for field selection in the current (3.x) Mongoose builds.

Prefix a field name you want to exclude with a -; so in your case:

Query.select('-Image');

Quick aside: in JavaScript, variables starting with a capital letter should be reserved for constructor functions. So consider renaming Query as query in your code.

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Model.findOne({ _id: Your Id}, { password: 0, name: 0 }, function(err, user){
// put your code
});

this code worked in my project. Thanks!! have a nice day.

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You could do this

const products = await Product.find().select(['-image'])
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In the updated version of Mongoose you can use it in this way as below to get selected fields.

user.findById({_id: req.body.id}, 'username phno address').then(response => {
res.status(200).json({
result: true,
details: response
});
}).catch(err => {
res.status(500).json({ result: false });
});
小开

I am use this with async await 

async (req, res) => {
try {
await User.findById(req.user,'name email',(err, user) => {
if(err || !user){
return res.status(404)
} else {
return res.status(200).json({
user,
});
}
});
} catch (error) {
console.log(error);
}
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I'm working on a feature. I store a userId array name "collectedUser" than who is collected the project. And I just want to return a field "isCollected" instead of "collectedUsers". So select is not what I want. But I got this solution.

This is after I get projects from database, I add "isCollected".

for (const item of projects) {
item.set("isCollected", item.collectedUsers.includes(userId), {
strict: false,
})
}

And this is in Decorator @Schema

@Schema({
timestamps: true,
toObject: {
virtuals: true,
versionKey: false,
transform: (doc, ret, options): Partial<Project> => {
return {
...ret,
projectManagers: undefined,
projectMembers: undefined,
collectedUsers: undefined
}
}
}
})

Finally in my controller

projects = projects.map(i => i.toObject())

It's a strange tricks that set undefined, but it really work.

Btw I'm using nestjs.

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You can do it like this

const products = await Product.find().select({
"image": 0
});
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For anyone looking for a way to always omit a field - more like a global option rather than doing so in the query e.g. a password field, using a getter that returns undefined also works

{
password: {
type: String,
required: true,
get: () => undefined,
},
}

NB: Getters must be enabled with option { toObject: { getters:true } }

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you can exclude the field from the schema definition by adding the attribute

    excludedField : {
...
select: false,
...
}

whenever you want to add it to your result, add this to your find()

find().select('+excludedFiled')

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