所以我正在创建一个音乐播放器,并希望从一个歌曲模式(已经创建)创建一个专辑模式。
在Album Schema中有一个专辑标题和一系列歌曲。现在我想将这些歌曲添加到相册中,如果它们具有相同的标题。
我该如何实现这一目标?
我已按照专辑标题对歌曲集进行了排序,但如果他们有相同的专辑标题,则不知道如何将歌曲添加到歌曲数组中。
//This is the song Schema.
var Song = mongoose.model('Songs', {
album: String,
title: String,
artist: String,
genre: String,
year: Number,
src: String
});
//This is the Album Schema.
const AlbumSchema = new Schema({
album: String,
songs: [{
title: String,
artist: String,
genre: String,
year: Number,
src: String
}]
});
还有一种方法可以在专辑架构中嵌套歌曲架构吗?
//Blank Array which stores AlbumSchemaObject
let AlbumSchemaArray = [];
//sample Object
let albumObj = {album:"abc",songs:[{title:"abc",artist:"abc",genre:"abc",year:"abc",src:"abc"}]}
//Data from Database
let dataFromMongo = someAlbumObj
//search in already stored Array Object
//if album names exists then fetch that Object
var searchedAlbumObj = AlbumSchemaArray.find((singleObj) => {
return singleObj.album === dataFromMongo.album;
});
//If object match then push songs in that objet
if(typeof(searchedAlbumObj.album) != "undefined")
{
searchedAlbumObj['songs'].push(dataFromMongo.songs)
}
else //creates new object and stores
{
AlbumSchemaArray.push(dataFromMongo)
}
我用find方法来检查是否分配了对象。如果不存在,我们将创建新对象并将其推送到一个数组(如果存在),我们将获取该对象并将歌曲推送到该对象。希望这会有所帮助
从您的架构设计,我得出结论,您计划只使用一个模型(Album集合的'Album'模型)。您已经为“歌曲”创建了一个架构。因此,不要在“相册”集合中重复字段,而是将“歌曲”模式嵌套在“相册”模式中。你可以这样做。
const mongoose = require("mongoose");
var Song = mongoose.Schema('Songs', {
album: String,
title: String,
artist: String,
genre: String,
year: Number,
src: String
});
const AlbumSchema = new Schema({
album: String,
songs: [Song]
});
然后你就可以创建你的'相册模型'了,
const Album = module.exports = mongoose.model("Album", AlbumSchema);
然后无论在哪里(也许是控制器!)你想要创建一首新歌,你都可以这样做,
let newSong = {
album: 'xxx',
title: 'xxx',
artist: 'xxx',
genre: 'xxx',
year: 'xxx',
src: 'xxx'
}
Album.update(
{ _id: album._id },
{ $push: { songs: newSong } }
);
如果您已经有一组歌曲,并且您需要查找特定专辑的歌曲,您可以使用:
Song.find({album: 'foo'})
.exec()
.then(songs => {
return Album.findOneAndUpdate({album: 'foo'}, {$push: {songs: songs}})
.exec()
})
.then(album => console.log(album))
.catch(err => err);
您的相册架构应如下所示:
const AlbumSchema = new mongoose.Schema({
album: String,
songs: [songSchema]
});
const Song = mongoose.model('Song', songSchema);
例:
songs : [ { _id: 5cb05ecd0facc60f8e383259, album: 'foo', title: 'song1' },
{ _id: 5cb05ecd0facc60f8e38325a, album: 'bar', title: 'song2' },
{ _id: 5cb05ecd0facc60f8e38325b, album: 'foo', title: 'song3' } ]
Song.find({album: 'foo'})
.exec()
.then(songs => {
return Album.findOneAndUpdate({album: 'foo'}, {$push: {songs: songs}})
.exec()
})
.then(album => console.log(album))
.catch(err => err);
// Code above gives you :
{ _id: 5cb05f8ee567df1092be74a9,
songs:
[ { _id: 5cb05ee5f1a14c0fc23f0c4d,
album: 'foo',
title: 'song1',
__v: 0 },
{ _id: 5cb05ee5f1a14c0fc23f0c4f,
album: 'foo',
title: 'song3',
__v: 0 } ],
__v: 0,
album: 'foo' }