创建后,如何填写一个子文档? [英] How to populate a sub-document in mongoose after creating it?
问题描述
我正在对item.comments列表添加评论。我需要在用户数据中输入comment.created_,然后才能在响应中输出。我应该怎么做?
Item.findById(req.param('itemid'),function(err,item){
var comment = item.comments.create({
body:req.body.body
,created_by:logged_in_user
});
项目。 comment.push(comment);
item.save(function(err,item){
res.json({
status:'success',
message :你已经评论过这个项目,
//如何填充comment.created_by这里???
comment:item.comments.id(comment._id )
});
}); // end item.save
}); // end item.find
我需要在我的res.json中填充comment.created_by字段输出:
comment:item.comments.id(comment._id)
/ pre>
comment.created_by是我的mongoose CommentSchema中的用户引用。它目前只给我一个用户ID,我需要填充所有的用户数据,除了密码和盐田。
这是人们问的模式:
var CommentSchema = new Schema({
body:{type:String,required:true}
,created_by:{type:Schema.ObjectId,ref:'User',index:true}
,created_at:{type:Date}
,updated_at:{type:Date}
} );
var ItemSchema = new Schema({
name:{type:String,required:true,trim:true}
,created_by:{type:Schema.ObjectId,ref: 'User',index:true}
,comment:[CommentSchema]
});
解决方案为了填充引用的子文档,您需要明确定义ID引用到的文档集合(如
created_by:{type:Schema.Types.ObjectId,ref:'User'}
)。
如果定义了这个引用,并且你的模式也被很好地定义了,你可以像往常一样调用
填充
(例如填充('comments.created_by')
)
概念验证码:
// Schema
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var UserSchema = new Schema({
name:String
});
var CommentSchema = new Schema({
text:String,
created_by:{type:Schema.Types.ObjectId,ref:'User'}
}) ;
var ItemSchema = new Schema({
comments:[CommentSchema]
});
//连接到DB和实例化模型
var db = mongoose.connect('在这里输入你的数据库');
var User = db.model('User',UserSchema);
var Comment = db.model('Comment',CommentSchema);
var Item = db.model('Item',ItemSchema);
//查找并填充
Item.find({})。populate('comments.created_by')。exec(function(err,items){
console.log (item [0] .comments [0] .created_by.name);
});
最后注意到
填充
仅用于查询所以您需要首先将您的项目传递到查询中,然后调用它:item.save(function(err,item) {
Item.findOne(item).populate('comments.created_by')。exec(function(err,item){
res.json({
status:'success',
消息:你已经评论过这个项目,
comment:item.comments.id(comment._id)
});
});
}) ;
I am adding a comment to an item.comments list. I need to get the comment.created_by user data before I output it in the response. How should I do this?
Item.findById(req.param('itemid'), function(err, item){ var comment = item.comments.create({ body: req.body.body , created_by: logged_in_user }); item.comments.push(comment); item.save(function(err, item){ res.json({ status: 'success', message: "You have commented on this item", //how do i populate comment.created_by here??? comment: item.comments.id(comment._id) }); }); //end item.save }); //end item.find
I need to populate the comment.created_by field here in my res.json output:
comment: item.comments.id(comment._id)
comment.created_by is a user reference in my mongoose CommentSchema. It currently is only giving me a user id, I need it populated with all the user data, except for password and salt fields.
Here is the schema as people have asked:
var CommentSchema = new Schema({ body : { type: String, required: true } , created_by : { type: Schema.ObjectId, ref: 'User', index: true } , created_at : { type: Date } , updated_at : { type: Date } }); var ItemSchema = new Schema({ name : { type: String, required: true, trim: true } , created_by : { type: Schema.ObjectId, ref: 'User', index: true } , comments : [CommentSchema] });
解决方案In order to populate referenced subdocuments, you need to explicitly define the document collection to which the ID references to (like
created_by: { type: Schema.Types.ObjectId, ref: 'User' }
).Given this reference is defined and your schema is otherwise well defined as well, you can now just call
populate
as usual (e.g.populate('comments.created_by')
)Proof of concept code:
// Schema var mongoose = require('mongoose'); var Schema = mongoose.Schema; var UserSchema = new Schema({ name: String }); var CommentSchema = new Schema({ text: String, created_by: { type: Schema.Types.ObjectId, ref: 'User' } }); var ItemSchema = new Schema({ comments: [CommentSchema] }); // Connect to DB and instantiate models var db = mongoose.connect('enter your database here'); var User = db.model('User', UserSchema); var Comment = db.model('Comment', CommentSchema); var Item = db.model('Item', ItemSchema); // Find and populate Item.find({}).populate('comments.created_by').exec(function(err, items) { console.log(items[0].comments[0].created_by.name); });
Finally note that
populate
works only for queries so you need to first pass your item into a query and then call it:item.save(function(err, item) { Item.findOne(item).populate('comments.created_by').exec(function (err, item) { res.json({ status: 'success', message: "You have commented on this item", comment: item.comments.id(comment._id) }); }); });
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