問題描述

我正在尋找為照片庫的 NoSQL 存儲構建合適的數據結構.在我的 Web 應用程序中，一張照片可以是 1 個或多個相冊的一部分.我有使用 MySQL 的經驗，但幾乎沒有使用過鍵值存儲.

I'm looking to build an appropriate data structure for NoSQL storage of a photo gallery. In my web application, a photo can be part of 1 or more albums. I have experience with MySQL, but almost none with key-value storage.

使用 MySQL，我將設置 (3) 個表，如下所示:

With MySQL, I would have set up (3) tables as follows:

photos (photo_id, title, date_uploaded, filename)
albums (album_id, title, photo_id)
album_photo_map (photo_id, album_id)

然后，要檢索 5 張最新照片的列表(帶有相冊數據)，查詢如下:

And then, to retrieve a list of the 5 latest photos (with album data), a query like this:

SELECT *
FROM albums, photos, album_photo_map
WHERE albums.album_id = album_photo_map.album_id AND
                photos.photo_id = album_photo_map.photo_id
ORDER BY photos.date_uploaded DESC LIMIT 5;

如何使用 NoSQL 鍵值對數據庫完成類似的查詢?(特別是亞馬遜的 DynamoDB.)存儲會是什么樣子?索引如何工作?

How would I accomplish a similar query using a NoSQL key-value pair database? (Specifically, Amazon's DynamoDB.) What would the storage look like? How would the indexing work?

推薦答案

使用 mongodb lingo，您的集合可能如下所示:

Using mongodb lingo, your collections could look like this:

photos = [
    {
        _id: ObjectId(...),
        title: "...",
        date_uploaded: Date(...),
        albums: [
            ObjectId(...),
            ...
        ]
    },
    ...
]

albums = [
    {
        _id: ObjectId(...),
        title: "..."
    }
]

查找 5 張最新照片的方法如下:

Finding the 5 newest photos would be done like this:

> var latest = db.photos.find({}).sort({date_uploaded:1}).limit(5);

mongo 中沒有服務器端連接，因此您必須像這樣獲取所有最新專輯:

There's no server-side joins in mongo, so you'd have to fetch all the latest albums like this:

> var latest_albums = latest.find({}, {albums: 1});

當然，那你必須把它歸結為一個集合.

Of course, then you have to boil this down into a set.

如果您只是將相冊嵌入照片文檔中，實際上會更容易，因為它們很小:

It's actually easier if you just embed the album inside the photo documents, since they're small:

photos = [
    {
        _id: ObjectId(...),
        title: "...",
        date_uploaded: Date(...),
        albums: [
            {name: "family-vacation-2011", title: "My family vacation in 2010"},
            ...
        ]
    },
    ...
]

那么查詢也是一樣的，只是你不必加入.查找相冊中的所有照片如下所示:

Then querying is the same, but you don't have to join. Finding all photos in an album looks like:

> db.photos.find({albums:{$elemMatch:{name: "family-vacation-2011"}}});

這篇關于用于 Web 照片庫的正確 NoSQL 數據架構的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！