如何从猫鼬的集合中排除一个特定字段? [英] How to exclude one particular field from a collection in Mongoose?
问题描述
我有一个带有Mongoose ODM( Mongoose 3.3.1 )的NodeJS应用程序.我想从集合中检索除1外的所有字段.例如:我有一个集合Product,其中有6个场,我想选择除"Image"外的所有场.我使用了"排除"方法,但出现了错误. 这是我的代码.
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);
}
});
但这会返回错误
Express
500 TypeError: Object #<Query> has no method 'exclude'.........
我也尝试过var Query = models.Product.find().exclude('title','Image');
和var Query = models.Product.find({}).exclude('title','Image');
,但是得到了相同的错误.如何从猫鼬的集合中排除一个/(两个)特定字段.
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.
推荐答案
使用 query.select
用于当前(3.x)猫鼬版本中的字段选择.
Use query.select
for field selection in the current (3.x) Mongoose builds.
用-
作为要排除的字段名称的前缀;所以在你的情况下:
Prefix a field name you want to exclude with a -
; so in your case:
Query.select('-Image');
简单点:在JavaScript中,应保留以大写字母开头的变量以供构造函数使用.因此,请考虑在代码中将Query
重命名为query
.
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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